Neurological neuropsychological - BMJ

Journal of Neurology, Neurosurgery, and Psychiatry 1985;48:799-806

Neurological and neuropsychological effects ofcerebral spinal fluid shunting in children with assumedarrested ("normal pressure") hydrocephalusRICHARD D TORKELSON*, LYAL G LEIBROCK,t JOHN L GUSTAVSON,tROBERT R SUNDELL§

From the Departments of Neurology, * Neurosurgery, t and Psychiatryt University ofNebraska MedicalCenter and the University of Nebraska College of Medicine§ Omaha, Nebraska

SUMMARY Normocephalic children found to have ventriculomegaly during evaluation of long-standing (4 5-8 5 years) neurological disorder were tested for academic achievement, intellectualquotient and neuropsychological functioning. Radioactive iodinated serum cisternography, preand post-shunt electrophysiological studies (visual evoked responses, brainstem auditory evokedpotentials, sleep electroencephalograms) and radiological studies (skull radiographs computedtomography) were recorded. Four children who have been followed more than one year afterinsertion of ventricular-peritoneal shunts are presented. All demonstrated improvement inpsychometric findings along with some improvement in CT scan and EEG studies. The mostmarked initial changes were noted on measures of neuropsychological performance, accom-panied later by improvement in measures of intelligence. Achievement test scores showed noconsistent pattern of change. This sample suggests that there is a group of asymptomatic childrenwith apparent clinically stable (arrested) hydrocephalus in whom abnormal neuropsychologicaltesting indicates the need for cerebrospinal fluid shunting, with subsequent improvement.

One occasionally discovers apparent asymptomaticventriculomegaly during examination of a child.Although the syndrome of normal pressure hydro-cephalus has been recognised in children for sometime,' 2 the literature on its diagnosis, treatment anddistinction from arrested" hydrocephalus remainslimited. Terms such as normal pressure hydro-cephalus,' occult hydrocephalus," or compen-sated hydrocephalus" are generally used to implythat the enlarged ventricles are of clinical impor-tance, and arrested hydrocephalus" to imply thatthe ventriculomegaly is no longer of pathologicalsignificance. A variety3 of clinical and laboratory

Address for reprint requests: Richard D Torkelson, MD, Director,Child Neurology, Department of Neurology, University of Neb-raska Medical Center, 42nd and Dewey Avenue, Omaha, Neb-raska. 68105, USA.

Presented in Part at the Eleventh Annual Interim Meeting Sectionof Pediatric Neurological Surgery, American Association ofNeurological Surgeons, San Francisco, California, USA, December10, 1982.

Received 7 February 1984 and in revised form 17 December 1984.Accepted 24 December 1984

evaluations have been utilised to help differentiatebetween these two states and include: changingneurologic findings, calculating excessive cranialgrowth velocity, noting ventricular angles and lackof air over the convexities on pneumoencephalogra-phy, assessing the response to repeated lumbarpunctures, finding features on cranial computedtomography (CT) such as periventricular hypo-density or sequential changes in measured volume,utilising radioisotope (RISA) cisternography toevaluate cerebrospinal fluid (CSF) flow and dynam-ics, employing short term continuous cerebral pres-sure monitoring, detecting alterations on cerebralblood flow studies, following changes in visuallyevoked potentials (VEPs) or slow burst activity inserial electroencephalograms (EEG) ,' using con-stant rate lumbar infusions to assess CSF absorptivecapacity,5 and recently servo-controlled variable-rate lumbar infusions.6 While most of these techni-ques can be of value when they are clearly abnor-mal, some, such as cranial growth velocity, can befrankly misleading; ' others, such as RISA cister-nography, have been demonstrated to have rela-tively poor sensitivity and specificity;"9 yet others,

799

Protected by copyright.

on January 20, 2022 by guest.http://jnnp.bm

j.com/

J Neurol N

eurosurg Psychiatry: first published as 10.1136/jnnp.48.8.799 on 1 A

ugust 1985. Dow

nloaded from

http://jnnp.bmj.com/

800

such as continual short term pressure monitoring,can be faulted as being assessments of the immedi-ate physiological status and possibly not alwaysreflecting the overall chronic state. Ultimately, how-ever, the success or failure of any diagnostic study or

studies used in making the decision whether to shuntis the intellectual fate of the patient.' ' I" As the goalis to preserve intellectual functioning, ideally one

would like a sensitive neuropsychological assess-

ment that could reliably detect early changes ofprogressive brain dysfunction, define a particularpattern of dysfunction that correlates with patholog-ical ventricular enlargement, help predict whichchildren would benefit from cerebrospinal fluiddiversion and be a sensitive tool to monitor theresults of the diversion procedure.

Neuropsychological assessment is a recent facet in

the evaluation of children, although these tech-niques have existed for some time for use in adults.Theoretically, these instruments are designed tomeasure functions which are more closely allied tobrain structure and function than are the more tradi-tional psychological tests." 12 It was hypothesisedthat since neuropsychological testing measures func-tions that are more directly mediated by the brainthan intellectual or achievement tests, they would bemore sensitive both to impairment associated withnormal pressure hydrocephalus and the immediatechanges that followed surgical alleviation. Alterna-tively, it was posited that traditional intelligencetests, which are assumed to measure more crystal-lised and higher integrative cortical functions, wouldbe less sensitive to the neuropsychological deficitsand to the immediate and anticipated changes fol-lowing shunting. Achievement testing, theoreticallydependent on training and the learning environ-ment, was thought likely to show the least amount ofchange after operation.

Methods

Patients were initially seen by one of the authors (RDT) ina general clinic for evaluation of chronic neurological dis-orders, none of the patients being referred because of sus-

pected intracranial pressure. When ventriculomegaly was

noted on the cranial CT scan, the patients were furtherassessed with skull radiographs, EEG during wakefulnessand sleep, VEPs, brainstem auditory evoked responses,

RISA cisternography and a battery of psychological testsincluding measures of academic achievement, intellectualability and neuropsychological functioning. As the childrenwere of differing ages, identical psychometric tests couldnot be administered to every child. Lumbar pressure

measurements were made during RISA cisternographyand ventricular pressure during shunt placement. Theelectrophysiological studies, CT scans and psychologicaltests were repeated at three to six month intervals follow-ing surgical correction of the hydrocephalic syndrome.

Torkelson, Leibrock, Gustavson, Sundell

The Luria-Nebraska Neuropsychological Battery wasutilised as the primary neuropsychological measure. Thisrecently developed battery has been extremely effective inthe assessment of brain functioning in adult popula-tions."1 12 The battery provides an assessment of elevenclinical areas including motor, rhythm, tactile and visualfunctions; receptive and expressive language abilities;basic writing, reading and arithmetic skills; memory andintellectual processes as well as several other empiricallyderived scales. The children's revision of this battery hasalso demonstrated considerable promise in the neurop-sychological assessment of youngsters."3 1 The Luria-Nebraska Neuropsychological Battery-Children's Revi-sion was developed using age-normed data and takes intoaccount the effects of maturation and learning. Althoughimprovement in actual performance would be expected asa youngster advances in age, test scores on this batterywould not change over time. Moreover, test-retest reliabil-ity studies have yielded significant results, suggesting goodstability and little variance with repeat testing.'3 Althoughextensive age-normed data are not available for the twoyoungest children in this study, applicable items from thebattery were administered to provide a baseline measure ofperformance. The Beery Development Test of VisualMotor Integration and the Finger Tapping Test were alsoused as neuropsychological indices. The Wechsler Scales,McCarthy Scales, and Peabody Picture Vocabulary Testwere employed as intellectual or IQ measures. Fourchildren have been followed for more than a year and arethe subject of this paper.

CasesCase 1: The oldest patient (10-5 years) was referred forevaluation of a reportedly stable left hemiparesis. Historywas sparse as she had been in multiple foster homes. Shebecame a ward of the state at 18 months of age followinginflicted traumatic bilateral subdural hematomas that weresuccessfully evacuated. Currently, her head circumferencewas at the 50th percentile, height and weight at the 15thpercentile. In addition to cocktail party" speech, she hada moderate left hemiparesis and spastic diplegia thoughcould ambulate well enough to participate in runninggames with only moderate difficulty. No history was eli-cited to suggest episodes of elevated intra-cranial pressure.The case worker who had known her for five years thoughther gait had not changed though was concerned about herincreasingly poor academic peformance. At the time ofshunt placement, her intracranial pressure was thought tobe mildly increased, though was not formally measured.Figure 1 shows CT scans before and after shunt insertion.Ventricular size diminished over the next year, but notimpressively so.On initial psychometric testing, the patient showed dif-

fuse organic impairment with deficits in all major areas ofneuropsychological functioning. Her performance on intel-lectual testing was at a levels below which a meaningful IQcould be calculated on either the Peabody or Wechslerscales. Similarly, achievement tests showed performance inreading and writing to be at levels below which standardscores are applicable. Arithmetic was at the low extreme ofreliable scores. Given the magnitude and pervasive nature



j.com/

J Neurol N


ugust 1985. Dow

nloaded from


Effects of CSF shunting in children with assumed arrested hydrocephalus

Fig I Case I

of her dysfunction, it was impossible to demonstrate reli-

able differences between various aspects of neurop-

sychological ability. On follow-up testing after insertion of

a shunt although the patient continued to exhibit a pattern

of diffusely impaired functioning relative to normal expec-

tations, with no measurable change on standardised intelli-

gence testing she manifested statistically significant

improvement on five of the eleven scales of the Luria-

Nebraska Neuropsychological Battery and improvement in

two others. Her greatest gains were noted on tasks asses-

sing motor and tactile functions; auditory attention, track-

ing and discrimination; expressive speech and intellectual

processes. Although initial follow-up achievement testing

revealed no appreciable changes, assessment one year fol-

lowing shunt placement showed gains in reading and spell-

ing. Since the tests are age-normed, these findings suggest

that the patient's trend of deteriorating performance has

reversed, at least for reading and spelling. The patient'smother has noted increased attention, concentration and

on-task behaviour consistent with that which might be

expected from the testing results.

Case 2: The second oldest patient (8 5 years) was refer-

red because ventriculomegaly had been noted during cer-

vical computed tomography for a single episode of lower

neck pain which resolved within 48 hours. She was in the

top quartile of her class. Detailed review of systems was

unremarkable. Because she was only 32 weeks gestationalage at birth and had neonatal hyperthryoidism, she hadinitially been closely followed and review of her old chartsshowed that the head circumference had gone from the 3rdpercentile to the 90th percentile in the first 21 months of

life, where it stayed. Currently, her head circumference

was at the 80th percentile, height and weight below the 3rd

percentile. (Her head size could be considered suspiciousin view of her short stature, though there was maternal

familial short stature.) Pre-shunt neurological examination

was normal, including the presence of spontaneous venous

pulsations on ocular examination. Figure 2 shows CT scans

before and after shunt insertion. One should note the well

defined cortical markings on the pre-operative CT. CSF

pressure at the time of shunt placement in the semi-

recumbent position was 150 mmH203Initial pyschological testing with this patient showed

intellectual functioning in the dull normal range and

Fig 2 Case 2

academic mastery in the low average range of ability.Neuropsychological evaluation revealed a diffuse patternof deficits with comparative strengths observed in tactilefunctions and visual processing skills. There was particularimpairment of higher cortical and integrative abilities.Follow-up neuropsychological evaluation showed a patternof statistically significant improvement in motor functions,auditory attention and discrimination abilities and someareas of rudimentary academic skills and general reasoningprocesses. Statistically significant changes were not foundon the latest standardised intellectual or achievement testsperformed nine months after shunt insertion.Case 3: The third oldest patient (5 5 years) was referredfor a second opinion to improve control of her left sidedfocal seizures. Although in the first grade, she was readingat the third grade level. History revealed she had beendelivered by elective caesarean section because ofcephalopelvic disproportion with birth weight, height andhead circumference all greater than the 75th percentile.Currently, height and weight were at the 75th, head cir-cumference at the 98th percentile. She had a left spastichemiparesis and additional mild spastic diplegia. Figure 3shows CT scan before and after operation. Postoperatively,the left ventricle is smaller and there is more cortical man-tle on the right, though the changes are not striking.

Initial psychometric testing showed this patient function-ing in the average range of intellectual ability, as estimated

Fig 3 Case 3

801



j.com/

J Neurol N


ugust 1985. Dow

nloaded from


802

by the Peabody Picture Vocabulary Test, but achievingaverage to superior on the Wide Range Achievement Test.It is noted that both parents had a background in educationand invested considerable effort in assisting her to acquireacademic skills. Although norms for the Luria-NebraskaBattery were not available for her age, selected items

measuring motor and tactile skills, rhythm and pitch dis-crimination, visual processing and memory functions were

administered from this instrument. She was also adminis-tered the finger tapping test and Development Test of Vis-ual Motor Integration. Generally, her performance on theneuropsychological assessment reflected impairment ofmotor and tactile skills in the left extremity, and compara-

tively poorer visual processing and visual-motor integra-

tion skills than verbal comprehension and reasoning

abilities. On post-operative testing, the patient showed a

significant gain in IQ though because of a ceiling effect,significant improvement was not recorded on achievementtesting. Noticeable improvement was observed in motor

coordination, writing and visual-motor integration suggest-ing greater cerebral integrity. Changes in motor speed or

tactile sensation were not apparent in the left hand. Addi-tionally, the patient was observed as more attentive andbetter able to stay on task compared to initial testing,though this had not been perceived as an area of concern

earlier. Complete seizure control occurred after shuntingwithout any increases in her anticonvulsants.Case 4: The youngest patient (4-5 years) was a ward ofthe state with long-standing stable left hemiparesis whowas referred for a pre-adoptive neurological examination.Premature at birth, she had Group B beta streptococcalsepsis and meningitis with a possible intraventricularhaemorrhage while in the neonatal nursery. She hadmeningitis again at 4¼/2 months of age. She was reportedlvdoing well in preschool. Currently. her head circum-

ference was at the 90th, height and weight were greaterthan the 98th percentile. In addition to cocktail party"speech, she had a mild left hemiparesis and additional mildspastic diplegia. Figure 4 shows CT scans before and aftershunt insertion.

Initial psychological evaluation demonstrated overallfunctioning in the dull normal range of ability, with a mar-

kedly higher Verbal than Performance IQ. As in the previ-

ous case, the patient was administered selected items fromthe Luria-Nebraska Battery and other neuropsychological

Fig 4 Case 4


measures to record baseline performance, though in manyareas normative performances were not available for herage. Evaluations showed visual processing skills andvisual-motor integrative abilities consistently deficientwhen compared to general verbal reasoning and other lan-guage mediated functions. Follow up testing demonstratedsignificant increases in measured intellectual ability withthe largest gains recorded in Performance and Full scaleIQ. She changed from a classification of dull normal to highaverage ability overall, and in Performance IQ, from bor-derline retarded to low average. A similar pattern wasnoted on the McCarthy scale. Dramatic improvement invisual processing and visual-motor integration abilitieswere demonstrated on the neuropsychologic tests. She wascapable of utilising visuo-spatial relationships and engag-ing in non-verbal problem solving at a level of significantlybetter than that seen preoperatively. Visual attention andtracking skills were also seen to increase and there wasslight improvement in unilateral motor coordination andspeed.

Results

These children share the common characteristics of:( 1) having ventriculomegaly discovered during theevaluation of other problems, (2) demonstratingnone of the classic clinical signs of clevated intracra-nial pressure, (3) having historical evidence ofinsults that would suggest their ventriculomegalywas long-standing, and (4) completing at least oneyear of serial psychometric testing following shuntplacement. No shunt-related complications havebeen encountered in the study group.The study protocol employed traditional neuro-

diagnostic methods along with standard intellectualassessments and a neuropsychological battery oftests undergoing adaptation to the paediatricpopulation called the Luria-Nebraska Neuro-psychologic Battery. Skull radiographs andelectrophysiologic studies generally were not helpful(Tables I and 2), with the exception of asynchron-ous asymmetry of sleep spindle activity during sleepEEGs which consistently improved after shunting.In evaluating patients with known past Xven-triculomegaly who are now being added to thestudy, we note serial CT scans may show littlechange over time. Likewise, even with marked intel-lectual improvement after shunting, as noted byothers,'` the CT changes may not be impressive.

In table 3 the left hand column summarises theoverall changes found using the neuropsychologicaltest batteries. These results were found at the firstevaluation performed three months after the place-ment of the shunts. The Wechsler Scales, McCarthyScales, and Peabody Picture Vocabulary Test wereemployed as intellectual or IQ measures. The resultsof these studies are summarised in the middle col-umn (table 3). Although testing at six to nine



j.com/

J Neurol N


ugust 1985. Dow

nloaded from


Effects of CSF shunting in children with assumed arrested hydrocephalusTable I Diagnostic results pre-shunt

Case VEP EEG ListernographY CT

I Bilaterally abnormal, Asynchronous asymmetry of sleep Abnormal with Ventriculomegaly involving bothO.S. latency greater spindles, diffuse atypical spike and ventricular tracer still lateral ventricles and third ventricle.than O.D. wave activity with sporadic multifocal present at 48 hours. Adjacent cortical low density suggests

spikes. focal cerebral porencephaly.Normal latencies. Asvnchronous asymmetry of sleep Ventriculomegaly involving both

spindles and K-complex activity during lateral ventricles and third ventricle.sleep recording.

3 Normal latency O.D.. Asynchronous asymmetrv of sleep Abnormal pathways. Ventriculomegaly involving bothabnormal latency 0.S. spindles, decreased voltage over right delayed activity in lateral ventricles, right far greater

hemisphere, multifocal right right ventricle (up to than left, and also the third ventricle.hemispheric spikes. 48 hours).

4 Normal latencics. Asvnchronous asymmetry of slcep Ventriculomegaly involving bothspindle and K-complex activity in slccp. lateral ventricles and third ventricle.mild slowing.

Table 2 Diagnostic results after-shunting

Case VEP LEIG CT

I No improvement of bilateral Infrequent asynchronous asymmetrv Limited improvement ofabnormalities. of sleep spindles, multifocal spikes. ventriculomegaly.No change in normal latencies. Rare asynchronous asvmmctrv of Improvement of ventriculomegaly

slecp spindles. with normal sized ventricles..3 No improvement OS, no change OD. Modest improvement of asynchronous Minimal improvement of

dsymmetrv of sleep spindles. ventricilomegalv.4 No change in normal latencies. Occasional asynchronous asvmmetry Improvement of ventriculomegaly with

of sleep spindles, no slowing. normal sized ventricles.

Table 3 Summarv ofpsychological test results

Case Age yr Luria neuropsyclhological Intellectual testing (IO) Achievement testing standard scores - 100no

Pre Post Pre PlostII 10. Significant improvemcnt in <40 Gilobal <40 Reading <46 6(0

7 of 11 scales 46 Verbal 46 Spelling <46 55<40 Pcrformance <- 4( Arithmetic 53 48

2 85 Signi'icant improvement in 89 93 Reading 98 976 of II scales Spelling 95 94

Arithmetic 91 8()3 5 5 Significant improvement in all 1(05 125* Reading '- 155 >155

applicable scales Spelling 143 145Arithmetic 124 133

4 4-5 Significant improvement in all 88 Global 1(04* Not formally tested by these testsapplicable scales 105 Verbal 1 16*

72 Pertormance 9 I

'Significant change

months demonstrated a trend toward increased IQwhen it occurred, the findings listed on the table arethose obtained one year following the shunt. TheWide Range Achievement Test summarised in theright hand column (table 3) provided an assessmentof academic performance and are the resultsobtained at the one year follow-up.

Because of the small sample of subjects, statisticalanalysis was not applied to the data; however, sev-eral trends are apparent on examination of theresults. The central hypotheses were largelyconfirmed. Initial baseline IQ testing and academicachievement testing were normal in the threeyoungest cases, though all the subjects showedsignificantly impaired performance on preoperative

Luria-Nebraska Neuropsychological testing. Follow-ing surgery, each of the subjects demonstratedimmediate and statistically significant improvementin the majority of areas assessed on the neuro-psychological testing. Similar increases were notseen immediately on measures of intelligence,though these were found in long-term follow-up. Onfinal assessment, the subject with initially slightlyabove average IQ produced a score in the superiorrange of ability. Of the two in the low average range,one improved her IQ score by a few statisticallyinsignificant points; however, the younger of the twomoved to the above average range which is statisti-cally significant. The oldest subject scored initially inthe severely retarded IQ range, though because the

803



j.com/

J Neurol N


ugust 1985. Dow

nloaded from


804

I( test employed did not measure below 40, we

could not be certain that there was no change. Inter-estingly, this subject did show significant gains on

neuropsychological testing suggesting the potentialfor later increase in IQ since there is a positive corre-

lation between these two measures. Additionally, byadaptive behavioural criteria she is not by strictdefinition retarded. This fact suggests she once had a

much higher IQ. Considering how long she presum-

ably had her normal pressure hydrocephalus, andthe apparent slower return the longer the conditionpersists, more observation time is necessary. For allpatients, achievement test scores did not changeappreciably. This finding suggests changes in theseareas were not directly commensurate with eitherincreasing chronological age or with the improve-ments noted on the other instruments.

Discussion

One of the major interests in this investigation was

the relative difference in results observed among thevarious psychometric measures used. Several obser-vations and conclusions were noted regarding thecharacteristics of the children in this study and therelationships of these characteristics to outcome as

measured on the psychological testing. First, subjectswho showed the most appreciable gains were thosewho were not substantially impaired in terms ofoverall IQ scores to begin with, though each demon-strated a pattern of disparity between verbal andvisual-motor performance skills, visual-motor skillsbeing worse than verbal skills. Deficits in visual-spatial relationships have long been described in

untreated hydrocephalic children,'6 though admit-tedly this pattern of difference is not uncommon inthe general population and is certainly not unique to

children with neurologic conditions.The second observation is that the two most

improved subjects had abnormal neuropsychologi-cal findings in the face of normal intelligence. It is

most probable that these youngsters had a premor-

bid higher intellectual potential which was impairedby the normal pressure hydrocephalus. Of note, on

the basis of preoperative intelligence testing alone,they probably would not have been referred forneurological evaluation. Importantly, the oldest sub-ject, who demonstrated severe retardation as well as

profound neuropsychological deficits, not onlyshowed the poorest follow-up performance but alsomade the least and slowest relative ,gains in

improvement. Although without a lo'ngitudinalstudy we cannot prove that her ventriculomegalywas the most chronic, the conclusion that the earlierthe shunt is placed the better the chance for normaldevelopment in patients with simple hydrocephalus


has previously been demonstrated in regard tohigher achieved IQ.'7

Third, although few consistent patterns of deficitswere noted among the results of the neuro-psychological testing, across the sample it was evi-dent that each subject showed difficulties in finepsychomotor functions. These difficulties were notalways apparent on gross examination but did showup on the more refined psychometrics. Deficits weretypically seen in the performance of rapid, sequen-tial, coordinated movements of the hands, particu-larly those requiring bilateral coordination. Similarfindings have been found in patients withmyelomeningoceles and presumed "arrested"hydrocephalus who benefited from shunting.'8 Inanother study of shunted 4-9-year-old patients with"uncomplicated" hydrocephalus and subsequentnormal sized ventricles, deficits in verbal and non-verbal memory, fine motor speed and coordination,and visual spatial problem solving were found,though a longitudinal study was not done to accesshow these deficits changed over time.'4 Short-termand intermediate memory deficits were also com-mon to three of our four subjects.

Fourth, variability or scatter in performance onthe neuropsychological subtests was a consistentfinding related to improvement. Again, the patternof strengths and weaknesses among the subjects wasnot entirely uniform; however, the fact that someareas were intact while others were significantlyimpaired (suggesting focal effects of the disease pro-cess) was associated with a favorable prognosis.

Fifth, it has been reported that preoperative serialtesting often shows psychomotor development notkeeping pace or even worsening with chronologicaldevelopment in children with myelomeningocelesand normal pressure hydrocephalus who stand tobenefit from shunting.'8 Similar conclusions areprobable from a study demonstrating that patientswith episodic non-functioning shunts and delays inrevisions have significantly lower IQ than those tre-ated promptly, and this was independent of thenumber of shunt revisions.'7 Because of the strikingabnormalities in the Luria-Nebraska Neuro-psychological Battery coupled with the standardneurodiagnostic techniques, our study did notinvolve pre-shunt serial examinations to verifydeterioration in standard IQ tests as we could notethically justify such a controlled study.

In summary, there is a population of children withenlarged ventricles, with few, if any, clinical com-plaints. Head circumference may not suggest theunderlying pathology, and the child may have per-formed at or above average intellectual levels foryears. Although usually there is some clinical evi-dence for a mild hyperreflexic diplegia when com-



j.com/

J Neurol N


ugust 1985. Dow

nloaded from


Effects of CSF shunting in children with assumed arrested hydrocephalus

paring the reflexes of the upper extremities to thelowers, the diplegia may be absent, subtle, presentbut non-progressive. The findings of spontaneousvenous pulsations, or, as we have found in patientsnow entering the protocol, monitored pressures thatare borderline or infreqently episodically elevated,suggest the pressure changes are not impressive andmust be searched for, as has been demonstrated tooccur in REM sleep.20One cannot rely on parental reports about the

progress of a child suspected of having normal pres-sure hydrocephalus, as the patient's maturationaldevelopment, achievement skills, and continuingstrengths in verbal abilities and adaptive behaviourmake cursory observation or testing unreliable.Simple intelligence testing is frequently non-specific,but the finding of higher verbal than performanceIQ coupled with ventriculomegaly on cranial CTscan, should raise strong suspicions of pathologicalcause and effect. The Luria- Nebraska Neuro-psychological Battery adds further diagnosticrefinement to psychological testing by more directlyassessing brain function and not crystallised func-tions or achievements. A scattering in subtests withimpaired performance in fine psychomotor functions(rapid, sequential, coordinated movements), short-term and intermediate memory deficits correlateswith improvement after shunting. Improvementafter shunting is first seen in the Luria-NebraskaNeuropsychological Battery followed later bychanges in traditional IQ testing, further strengthen-ing its possible predictive value. Lastly, presumablythe longer there is delay in recognition of thepathological state, the greater the impact on theultimate morbidity. Several children too young (lessthan four year of age) were not included in thisreported series because of the current age limita-tions of the Luria-Nebraska Neuropsychiatric Bat-tery. Although they also demonstrated improve-ment in age-normed developmental assessments,efforts are currently underway to extend the agelimits of this test downwards to include this impor-ant group of children

Clearly, the present findings are preliminary inthe understanding of the intellectual and neuro-psychological aspects of normal pressure hy-drocephalus in the paediatric age group. Furtherlongitudinal study in this area with larger samples ofsubjects are needed and should prove valuable inenabling one to identify patients who stand tobenefit from shunting and perhaps provide insighton the manner in which normal pressure hyd-rocephalus affects intelligence.

ReferencesMilhorat TH, Hammock MK: Arrested" versus normal

pressure hydrocephalus in children. Clin Proc ChildHosp Natl Med Cntr 1972;28:168-73.

2 Milhorat TH. Hydrocephalus and the Cerebral SpinalFluid. Baltimore: Williams and Wilkins, 1972:182-5.

3 Schutz H, Fleming JFR, Humphreys RP, Deck JHN,Keith WS. Normal pressure hydrocephalus-highpressure Normocephalus. Can J Neurol Sci1980;7:211-9.

Hashi K, Nishimura S, Kondo A, Nin K, Jac-Hong S.The EEG in normal pressure hydrocephalus. ActaNeurochir 1976;33:23-35.

5 Di Rocco C, Caldarelli M, Maira G, Rossi GF. The studyof cerebrospinal fluid dynamics in apparently"arrested" hydrocephalus in children. Childs Brain1977;3: 359-74.

6 Sklar FH, Beyer CW Jr, Ramanathan M, Clark WK.Servo-controlled lumbar infusions in children, a quan-titative approach to the problem of arrested hyd-rocephalus. J Neurosurg 1980; 52: 87-98.

Schick RW, Matson DD. What is arrested hyd-rocephalus? J Pediatr 1961;58:791-9.

6 Black PMcL. Idiopathic normal pressure hydrocephalus;results of shunting 62 Patients. J Neurosurg1980;52:371-7.

Belloni G, Di Rocco C, Focacci C, Galli G, Maira G,Rossi GF: Surgical indications in normotensive hyd-rocephalus. A retrospective analysis of the relations ofsome diagnostic findings to the results of surgicaltreatment. Acta Neurochir 1976;33: 1-21.

'0 Gordon N. Normal pressure hydrocephalus and arrestedhydrocephalus. Dev Med Child Neurol1977; 19:540-3.

"Golden CJ, Purisch AD, Hammeke TA. The Luria-Nebraska Neuropsychological Battery-A Manual forClinical and Experimental Uses. Lincoln: University ofNebraska Press, 1979.

2Golden CJ, Hammeke TA, Purisch AD, et al. ItemInterpretation ofthe Luria-Nebraska Neuropsycholog-ical Battery. Lincoln: University of Nebraska Press,1982.

3 Golden CJ. Luria-Nebraska Battery: Theory and For-mulation. In: Hind GW, and Obrzut JE, eds. Neuro-psychological Assessment and the School Age Child.New York: Grune and Stratton, 1981.

4 Plaisted JR, Gustavson JL, Wilkening GN, Golden CJ.The Luria-Nebraska Psychological Battery-TheChildren's Revision: theory and current researchfindings. J Clin Child Psychol 1983; 12:13-21.

'5 Jacobs L, Kinkel W. Computerized axial transversetomography in normal pressure hydrocephalus.Neurology (Minneap) 1976; 26: 501-507.

16 Miller E, Sethi L. The effect of hydrocephalus on per-ception. Dev Med Child Neurol 1971;Supplement25:77-81.

'' Raimondi AJ, Soare P. Intellectual development inshunted hydrocephalic children. Am J Dis Child1974; 127:664-671.

18 Hammock MK, Milhorat TH, Baron IS. Normal pres-sure hydrocephalus in patients with myelomenin-gocele. Dev Med Child Neurol 1976;Supplement37:55-68.

Prigatano GP, Zeiner HK, Pollay M, Kaplan RJ.

805



j.com/

J Neurol N


ugust 1985. Dow

nloaded from


806

Neuropsychological functioning in children withshunted uncomplicated hydrocephalus. child's Brain1983;10: 112-20.

20) Di Rocco C, McLone DG, Shimoji T, Raimondi AJ.


Continuous intraventricular cerebrospinal fluid pres-sure recording in hydrocephalic children during wake-fulness and sleep. J Neurosurg 1975;42:683-9.



j.com/

J Neurol N


ugust 1985. Dow

nloaded from


Documents

Neurological neuropsychological - BMJ