WEAKNESSETIOLOGY NEUROLOGIC

Upper Motor Neuron Lesion­ Cortex: CVA, tumor, hydrocephalus, infection, MS, drugs,

toxins, metabolic encephalopathy­ Basal ganglia: neuroleptics, parkinson’s, Huntigntons­ CB: tumor, MS, alcohol, pernicious nameia, spinocerebellar

and freidrick’s ataxia­ SC: tumor, trama, MS, pernicious anemia, epidural absess,

transverse myelitits, cervical spondylosis, poliomyelitis­ MN: ALS

Lower Motor Neuron Lesion­ PN: plexopathy, compression, diabetes, GBS, vasculitis,

shingles, B12, alcohol, drugs, Pb, uremic, charcot marie­ NMJ: myasenia gravis, Eaton Lambert, Botulism, Tick

paralysis, diptheria, ciuatera poisoning, shellfish or pufferfish poisoning

­ Muscle: polymyositis, dermatomyositis, alcoholic myopathy, thyroid, cushings, steroid myopathy, hypokalemia, hypophosphatemia, muscular dystrophy

VASCULAR Myocardial ischemia Dehydration Sepsis/infections

HEMATOLOGIC Anemia Hematologic cancers: lymphoma, leukemias

ENDOCRINOPATHY Hypothyroidism Adrenal failure Hypoglycemia

OTHER Cancer Anxiety Fibromyalgia Chronic Fatigue Syndrome

HISTORICAL PEARLS IN THE WEAK PATIENT Respiratory symptoms: think pneumonia Delirium in elderly: think UTI and sepsis Recurrent episodes of global weakness in young, healthy: periodic hypokalemic paralysis Ascending paralysis and areflexia: Guillian-Barre’ syndrome Weakness with PDDD complaints: myasenia gravis Rapidly progresive paralysis with spinal level and UMN signs: transverse myelitis Looks like Guillan-Barre’ but history of tick bite or tick found: tick paralysis

OXYGENATION AND VENTILATION Patients that present with weakness may be in respiratory failure Early respiratory failure may be difficult to detect clincially Respiratory bedside function tests will help detect respiratory failure

Forced Vital Capacity (FVC) < 10 - 12 ml/kg indicates respiratory failure Negative Inspiratory Force (NIF) < 20 cm H20 indicated respiratory failure

Address level of care before intubation BiPAP not indicated b/c these conditions are generally not rapidly reversible Indications for intubation

RR < 10 or RR > 35 Severe fatigue Inability to protect airway Inability to handle secretions Rapidly rising PC02 Hypoxemia despite supplemental oxygen FVC < 12 ml/kg NIF < 20 cmH20

Rapid Sequence Induction AVOID SUCCINYLCHOLINE!!

Box 12-1

DTRs PLANTARS TONE SENSATION

UMN Increased Upgoing Increased to spastic

Normal or decreased

LMN Decreased or absent

Normal or absent

Decreased to flaccid

Decreased

NMJ +MUSCLE

Normal or decreased

Normal or absent

Decreased to flaccid

Normal

APPROACH TO THE NEUROLOGICAL PATIENTWHAT IS THE NEUROLOGICAL LEVEL? Is there a pattern of UMN or LMN signs

UMN­ Increased tone­ Hyperreflexia­ Upgoing plantars­ Atrophy less common

LMN­ Decreased tone­ Hyporeflexia­ Downgoing or absent plantars­ Atrophy more common

Specific level patterns

Cerebrum: seizures, dementia, delirium, aphasia, agnosia, apraxia, amnesia, personality change, hemiparesis, coma

Brain Stem: cranial neuropathies, alternating sensory loss, alternating motor loss, coma, absent brainstem reflexes

Basal Ganglia: rigidity, chorea, athetosis, bradykinesis, resting tremor Cerebellum: ataxia, intention tremor Spinal Cord: paraparesis, quadriparesis, sensory level, bowel and bladder

sx Motor Neuron: fasciculations Peripheral nerve: stocking and glove sensory loss, ascending paralysis,

areflexia, localized pain and numbness Neuromuscular junction: ptosis, diplopia, dysphagia, dysarthria,

fatiguability without numbness Muscle: symmetrical proximal weakness without sensory loss

IS THE LESION FOCAL OR DIFFUSE? Focal Lesions

Developmental Trauma Tumor Stroke Inflamamtion

Diffuse Lesions Inflammation and Autoimmune Nutritional and Toxic Metabolic and Endocrine Degenerative

WHAT IS THE SPECIFIC PATHOLOGY? Setting: trauma, toxic exposures Time-course: acute, subacute, relapsing, chronic, progressive Special symptoms: headache, fever

CORTEXTRAUMA EDH SDH SAH CONTUSION DAI

TUMOR Primary Metastatic disease

STROKE TIA/infarct

ICH SAH SDH

INFLAMMATION MS Lupus cerebritis Vasculitis

INFECTION Encephalitis Meningitis Brain abscess

NUTRITIONAL/TOXIC Drugs Alcohol B12 dementia Sedatives, hypnotics, opiods, etc

METABOLIC/ENDOCRINE METABOLIC mneumonic (see ALOC notes)

DEVELOPMENTAL/DEGENERATIVE Cerebral palsy Mental Retardation Alzheimers Other Dementia

NEURONAL ACTIVITY Seizure

BASAL GANGLIATRAUMA Punch Drunk syndrome

STROKE TIA/infarct ICH: hypertensive bleeds common

NUTRITIONAL/TOXIC Extrapyramidal Side-effects of Neuroleptics

Akathesias Dystonic reactions Tardative dyskinesia Parkinsonian reaction Neuroleptic malignant syndrome

DEVELOPMENTAL/DEGENERATIVE Parkinson’s Huntington’s chorea

BRAIN STEMTRAUMA Uncal herniation Transtentorail herniation Tonsillar herniation

TUMOR Primary Mets

STROKE SAH ICH TIA Infarct Any stroke with herniation syndrome Basilar artery migraine Basilar tip thrombosis Vertebral dissection

NUTRITIONAL/TOXIC Wernickes encephalopathy (DOA)

INFLAMMATORY Multiple sclerosis Acute Disseminated Encephalomyelitis (KIDS)

BRAIN STEM SEIZURE

CEREBELLUMTRAUMA SDH EDH CONTUSION

TUMOR

Primary: especially kids Mets

STROKE SAH ICH TIA Infarct Any stroke with herniation syndrome Basilar artery migraine Basilar tip thrombosis Vertebral dissection

NUTRITIONAL/TOXIC Alcholic cerebellar degeneration: vermis (legs > arms) Pernicouis anemia Drug toxicity

Dilantin Anticonvulsants Lithium

INFLAMMATORY Multiple sclerosis Post infectious cerebellitis

DEGENERATIVE/DEVELOPMENTAL Cerebral palsy Spinocerebellar ataxia Friedrick’s ataxia

SPINAL CORDTRAUMA EDH SDH CONTUSION FRACTURE COMPRESSION

TUMOR Primary Metastatic disease Bone mets that push on cord (breast, prostate, etc)

STROKE TIA/infarct: thrombosis, embolism (endocarditis etc)

Vasculitis Aortic dissection AAA rupture Spontaneous hemorrhage into epidural space or cord

INFLAMMATION MS Transverse myelitis Vasculitis

INFECTION Meningitis

NUTRITIONAL/TOXIC Alcohol B12 deficiency

DEVELOPMENTAL/DEGENERATIVE Cervical spondylosis Spina bifida

PERIPHERAL NERVETRAUMA Brachial plexopathy Lumbar plexopathy Compartment syndroms Carpel tunnel Sat nigh palsy Radiculopathy Ulnar nerve palsy Etc

TUMOR Pancoast syndrome Acoustic neuroma

STROKE Diabetic nerve infarcts Diabetic third nerve palsy Vasculitis

INFLAMMATION Guillan-Barre

Brachial neuritis Vasculitis

INFECTION Shingles

NUTRITIONAL/TOXIC Alcohol B12 Thiamine (beriberi) Many drugs: HIV Rx, chemotherapy, etc Metals: Pb, mercury, arsenic Organophosphastes

METABOLIC/ENDOCRINE Diabetic peripheral neuropathy]\ Uremic peripheral neuropathy Porphyreas

DEVELOPMENTAL/DEGENERATIVE Charcot Marie Tooth

NEUROMUSCULAR JUNCTION

Myasenia GravisEaton Lambert syndromeBotulismTetanusTick paralysisNMJ blockageOrganophosphatesFish toxicity

Ciguatera poisoningTetrodotoxin

MUSCLE

PolymyositisDermatomyositisTrichinosisAlcoholic MyopathyHypothyroidismCushingsSteroid myopathyHypokalemia

Any causeFamilial periodic paralysisThyrotoxic periodic paralysis

HypophosphatemiaHypercalcemiaHypocalcemiaMuscular dystrophysSpinal Muscular Atrophy