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