Acute Peripheral Weakness Peter Shearer, MD Assistant Residency Director Mt. Sinai School of Medicine

Peter Shearer, MD Objectives l Acute Extremity Weakness l Levels of potential involvement _Key Elements of History and Physical for each level CNS PNS l Diagnostic Options l Therapy

Peter Shearer, MD Question #1 At which level of the CNS can a lesion produce motor weakness without affecting mental status? A. Brainstem B. Dorsal root ganglia C. Spinal Cord D. Cerebellum

Peter Shearer, MD Question #2 Which of the following can differentiate between acute transverse myelitis and Guillain-Barre Syndrome? A. ascending vs. descending paralysis B. presence of slight lymphocytosis in CSF C. increased vs. decreased reflexes D. acuity of onset E. presence of a preceding respiratory or GI illness

Peter Shearer, MD Question #3 Which of the following does NOT produce a myelopathy? A. Spinal cord infarct B. Transverse Myelitis C. Spinal cord metastasis of lung cancer D. Tick Paralysis

Peter Shearer, MD Question #4 Which of the following illnesses has a well evaluated, prospectively studied therapy? A. Guillain-Barre Syndrome B. Acute Transverse Myelitis C. Acute Spinal Cord Hemorrhage D. Botulism

Peter Shearer, MD case-history l 30 year old woman l diffuse weakness l lower extremities > upper extremities l over 3 days l preceding diffuse vesicular rash l difficulty voiding

Peter Shearer, MD case-history l 30 year old woman l diffuse weakness l lower extremities > upper extremities ascending l over 3 days l preceding diffuse vesicular rash l difficulty voiding

Peter Shearer, MD case-details of the physical l BP 140/86, P 90, RR 18, T 99, 99%O 2 sat l CN intact l Motor: 4/5 in UE, 3/5 in LE l Sensory intact but sharp/dull less pronounced in the LE l Reflexes 3+ in all extremities l palpable bladder

Peter Shearer, MD Case - summary l Acute ascending symmetrical paralysis following a recent infection with slight sensory impairment and hyperreflexia.

Peter Shearer, MD Could this be a CNS lesion?

Peter Shearer, MD Could this be a CNS lesion? Yes Can a CNS lesion produce bilateral weakness and sensory deficits and have a normal mental status?

Peter Shearer, MD Could this be a CNS lesion? l CNS = Upper motor neuron _cerebral cortex to, but not including the anterior horn cell l UMN lesions produce: _increased tone _increased DTR _extensor plantars _no fasiculations

Peter Shearer, MD levels of the CNS l Cerebral Cortex l Cerebellum l Brainstem l Spinal Cord up to the Anterior Horn Cell

Peter Shearer, MD Could this be a PNS lesion?

Peter Shearer, MD Could this be a PNS lesion? Yes Where?

Peter Shearer, MD levels of the PNS l Spinal cord - Anterior horn cell of the Lateral Corticospinal tract l Peripheral nerve l NMJ l Muscle

Peter Shearer, MD Myelopathy l A Lesion in the cord produces A Level of deficit l Division of labor _Dorsal columns - position/vibration _Lateral corticospinal tract - motor function _Lateral spinothalamic tract - pain/temperature l Preserved mental status

Peter Shearer, MD Myelopathy - etiology l Infarct l Trauma _Brown-Sequard _Central cord syndrome _Anterior cord syndrome l Mass lesions l Inflammation/Infection

Peter Shearer, MD myelopathy - details of history l Acuity of onset l Trauma l Distal > Proximal l Pain at site l Preceding Illness

Peter Shearer, MD myelopathy - details of physical l Weakness l Spasticity l Atrophy l Fasciculations l Bowel and bladder complaints l Increased tone l Sensory findings l DTR’s may be increased (not if ALS)

Peter Shearer, MD Cord Infarct l Anterior Spinal Artery _anterior cord - dissociation of sensory findings _symmetric flaccid paralysis _loss of sphincter tone _Dorsal columns prevail l Posterior Spinal Artery _proprioceptive and vibratory sensation

Peter Shearer, MD Acute Peripheral Neuropathy l Motor and/or sensory _disorder of transmission along peripheral nerve axon myelin _Guillain-Barre _Tick Paralysis _Toxic

Peter Shearer, MD Acute Peripheral Neuropathy - details of physical l Weakness l Absent DTR’s (all outflow from the cord is affected) l Affects longer nerves first - ascending

Peter Shearer, MD Guillain-Barre Syndrome l Post infectious l mononuclear inflammatory infiltrate of myelin l dymyelinating l may be axonal injury and degeneration

Peter Shearer, MD Guillain-Barre Syndrome l Symmetric ascending paralysis l areflexic l possible sensory - paresthesias, position and vibration l Progression over weeks - may be more rapid l 1/3 progress to respiratory failure

Peter Shearer, MD Guillain-Barre Syndrome l CSF - Albuminocytologic dissociation l Stool for C. jejuni

Peter Shearer, MD NMJ l Presynaptic - disorder of ACh release _will affect nicotinic and muscarinic _weakness _anticholinergic symptoms l Postsynaptic - will just be nicotinic _weakness _NO anticholinergic findings

Peter Shearer, MD NMJ - details of history l Exposure _botulism _snake bites l fatigue

Peter Shearer, MD NMJ - details of physical l Proximal>distal muscles l Bulbar muscles l May have anticholinergic signs if presynamptic l Fatigability

Peter Shearer, MD Examples of NMJ disorders l Myasthenia Gravis l Botulism l Tick Paralysis

Peter Shearer, MD Myopathies l Periodic Paralyses l Electrolyte Abnormalities _Hypermagesemia _Hypophosphatemia

Peter Shearer, MD Metabolic Abnormalities l Periodic Paralyses l Hypermagesemia l Hypophosphatemia

Peter Shearer, MD Work up l CBC and serum chemistry l CSF for signs of GBS or myelitis l Radiography _MRI vs CT

Peter Shearer, MD Management l Corticosteroids _not supported by prospective placebo controlled studies