10-11 Gbs General Neuro 2nd Year

7/29/2019 10-11 Gbs General Neuro 2nd Year

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GUILLAIN-BARRE SYNDROME


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GBS

Eponym that encompasses acute immune-

mediated polyneuropathies

Peripheral nerve myelin is target of an immuneattack

Starts at level of nerve root=conduction blocks &

muscle weakness

Eventually get widespread patchy demyel=increased paralysis


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PATHOPHYSIOLOGY

Usually postinfectious

Immune-mediated: infectious agentsthought to induce Ab production against

specific gangliosides/glycolipidsLymphocytic infiltration of spinal

roots/peripheral nerves & then macrophage-mediated, multifocal stripping of myelin

Result: defects in the propagation ofelectrical nerve impulses, with eventualconduction block and flaccid paralysis


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CLINICAL FEATURES:

Progressive, fairly symmetric muscle weakness

-typically starts in proximal legs

-10% will 1st develop weakness in face or arms

-severe resp muscle weakness in 10-30% pts

-oropharyngeal weakness in ~ 50%

Absent or depressed DTR

Often prominent severe pain in lower back

Common to have paresthesias in hands and feet

Dysautonomia is very common: tachycardia, urinaryretention, hypertenison alternating w/ hypotension,ileus


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DIAGNOSIS:

Albuminocytologic dissociation: elevated CSFprotein w/ normal WBC (80-90% pts)

Electromyography (EMG) helps confirm diagnosis =prolonged or absent F waves


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NINDS EXPERT CONSENSUS:

Reqd Features for dx:

1. Progressive weakness of > than 1 limb

2. Areflexia

Supportive Features:~progression of Sx over days to 4 weeks

~relative symmetry

~CN involv esp b/l facial n weakness

~autonomic dysfunction ~EMG features

~elev CSF protein w/ cell count ,10 mm3


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GBS=HETEROGENOUSSYNDROMEW/VARIANTFORMS

Think of AIDP as the traditional form asdescribed previously, accts for 85-90%

Miller Fisher Syndrome: opthalmoplegia,

ataxia, and areflexia (5%). GQ1b antibody. Only1/4th w/ extremity weakness

AMAN: selective involv of motor nerves, DTRsare preserved, more common in Japan/China,almost all preceded by Campylobacter infxn

AMSAN: more severe form of AMAN +sensory


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DDXOF POLYNEUROPATHY:

Arsenic poisoning

N-Hexane (glue sniffing)

Vasculitis

Lyme DiseaseTick paralysis

Sarcoidosis

Leptomeningeal Dz

Paraneoplastic Dz

Critical Illness


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SUPPORTIVE CARE

Monitor Resp status closely (follow NIFs), up to30% may req ventilatory support

In severe cases, intrarterial monitoring may benecessary given the gisngifcant blood pressurefluctuations

Neuropathic pain plagues most, often managed w/Gabapentin or Carbamazepine


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DISEASE MODIFYING TREATMENT

IVIG : typically given for 5 d at 0.4 gram/kg/d(may need to extend course depending onresponse)

Plasmapheresis: usually 4-6 treatments

over 8-10 days

The choice b/w plasma exchange and IVIG isdep on availability, pt contraindications, etc.

Because of ease of administration, IVIG isfrequently preferred. The cost and efficacyof the 2 treatments are comparable.Glucocorticoids have NO ROLE!!


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OUTCOMES:

65% can walk independently @ 6 mos

Overall, 80% usually recover completely

5-10% have prolonged course w/ incompleterecovery, ~3% wheelchair bound

Approx 5% die despite ICU care

2% will develop chronic relapsing ChronicInflammatory DemyelinatingPolyradiculoneuropathy (CIDP)


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REFERENCES:

Plasmapheresis and acute Guillain-Barre syndrome.The Guillain-Barre Syndrome Study Group.Neurology 1984; 2:1296.

Ropper, AH. The Guillain-Barre Syndrome. N Engl JMed 1992; 326:1130.

Sumner, AJ. The physiologic basis for symptoms inGuillain-Barre Syndrome. Ann Neurol 1981; 9Suppl:28.


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TICKSPARALYSIS Tick paralysis is the only tick-borne disease that is not

caused by an infectious organism. The illness is caused bya neurotoxin produced in the tick's salivary gland. Afterprolonged attachment, the engorged tick transmits the toxinto its host. The incidence of tick paralysis is unknown.

Clinical features:

Beginning with weakness in both legs that progresses toparalysis. The paralysis ascends to the trunk, arms, andhead within hours and may lead to respiratory failure anddeath. The disease can present as acute ataxia withoutmuscle weakness.

Patients may report minor sensory symptoms, butconstitutional signs are usually absent. Deep tendonreflexes are usually hypoactive or absent, andophthalmoplegia and bulbar palsy can occur.


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TICK


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CHRONICINFLAMMATORYDEMYELINATINGPOLYNEUROPATHY (CIDP)

Both GBS and CIDP are similar most, there areshuttle changes.

Similarities

an increased CSF protein a demyelinative type of nerve conduction

abnormality

probable autoimmune pathogenesis, and an

inflammatory pathology.


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DIFFERENCES

A preceding illness is relatively uncommon in patients withCIDP. Whereas GBS is an acute (rarely sub acute)

monophasic illness

CIDP evolves more slowly either in a steadily progressiveor stepwise manner (sometimes in an asymmetric pattern)and attains its maximum severity only after weeks, months

or longer, following which it tends to run a relapsing orfluctuating course.

Most cases of CIDP respond favourably to the prolongedadministration of corticosteroids, as well as to plasma

exchange and, in many cases, to intravenous to immuneglobulin


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PERONEAL MUSCULAR ATROPHY (CHARCOT-MARIE-TOOTH DISEASE)

Inherited neuropathy

Autosomal dominant trait

Onset

Late childhood or adolescence, with atrophy of muscles ofthe feet and legs and later of the hands and arms


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CLINICALFEATURES

The early involvement of the peronei and extensors of the

toes produces an equinovarus deformity and clawfoot. Deep and superficial sensation are impaired, usually to a

slight degree, and tendon reflexes are absent in theaffected limbs.

The illness progresses very slowly, with long periods ofstability.

Wasting seldom extends above the elbows and the lowerthird of the thighs.

Sensory ataxia and weakness --- instability in gait


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DIABETIC NEUROPATHIES

Diabetic ophthalmoplegia

Acute mononeuropathy

Lumbar mononeuropathy multiplex

proximal diabetic neuropathy distal sensory type

autonomic involvement

Segmental radiculopathy


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DIABETICOPHTHALMOPLEGIA

Infarction of the 3rd or 6th cranial nerve

Occular palsy associated with severe pain aroundthe eye and forehead

Pupillary constriction ??????

The pupilloconstrictor fibers, located peripherally inthe third nerve, are spared by the infarction, which

characteristically affects the central portion of thenerve; hence, pupillary function is usually intact


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ACUTEMONONEUROPATHY

Femoral and sciatic nerve most commonly affected


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LUMBARMONONEUROPATHYMULTIPLEX

Diabetic amyotrophy

subacutely evolving, painful, asymmetric orunilateral, predominantly motor neuropathy,affecting multiple lumbosacral nerves.

Muscle weakness and atrophy are most evident inthepelvic girdle and thigh muscles on one side andthe knee jerk is lost.

Recovery time more months


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PROXIMALDIABETICNEUROPATHYI

symmetric weakness and wasting of the pelvic andproximal thigh muscles, of insidious onset andgradual evolution.

Scapular and upper arm muscles are affected lessfrequently.

Pain is not a consistent feature, and sensorychanges, if present, are mild and of the distalsymmetric type.


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DISTALSENSORYTYPE

This takes the form of persistent and oftendistressing pain, numbness, and tingling, affectingthe feet and lower legs symmetrically.

In severe cases, the hands may be affected.

Occasionally deep sensation is impaired, withataxia and bladder atony (diabetic pseudotabes)


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AUTONOMICINVOLVEMENT

pupillary and lacrimal

dysfunction, impairment of sweating and vascular reflexes,nocturnal diarrheoa, atonicity of the gastrointestinal tractand bladder, impotence, and postural hypotension.

These symptoms are frequently combined with other formsof diabetic neuropathy, particularly with the distal sensorytype


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SEGMENTALRADICULOPATHY

common complication of long-standing diabetes,presenting with severe pain, dysesthesia, andsuperficial sensory loss in a segmental distributionover the chest or abdomen.

The EMG changes (fibrillations of paraspinalmuscles in multiple myotomes) confirm thepresence of a widespread radiculopathy


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10-11 Gbs General Neuro 2nd Year