Clinical Localization in Neurology PDF

Clinical Localization In Neurology Dr Angus Nisbet Consultant Neurologist & Sleep Physician Essential Kit WB Sauders 2000 Diagnostic Process • History • Possible Pathology (tempo) • Possible Anatomy • Disease elucidating questions • Examination • Confirmation or exclusion of Anatomy • Identi...

Clinical Localization In Neurology Dr Angus Nisbet Consultant Neurologist & Sleep Physician Essential Kit WB Sauders 2000 Diagnostic Process • History • Possible Pathology (tempo) • Possible Anatomy • Disease elucidating questions • Examination • Confirmation or exclusion of Anatomy • Identification of other clues to pathology • eg rash, carotid bruit, papilloedema, functional weakness Symptom Onset & Progression - Pathology • Sudden with improvement: vascular, trauma • Overnight: Vascular, demyelinating, compression • Minutes: migraine • Hours to days: demyelination • Weeks to months: malignant neoplasm • Years: benign neoplasm, mechanical compression, primary progressive MS, or degenerative • Precipitating / Modifying factors Domains of Deficit Motor • Limbs • • • • • • Weakness Wasting / Fasciculation Ataxia / clumsiness Loss of dexterity Hypokinesia & bradykinesia Apraxia • Gait & Posture • • • • • Spasticity Ataxia High-stepping Waddling Shuffling • Speech • Dysphonia • Dysarthria • Dysphasia • Swallowing • Dysphagia • Nasal regurgitation • Autonomic (motor & sensory) • • • • Hypotension Gastroparesis / constipation Bladder / sexual function Pupil abnormalities Sensory 1. Sensory • • • • Numbness (superficial sensory loss) Akinaesthesia (propioceptive loss) Paraesthesia Allodynia / hyperpathia (altered pain) 2. Vision • Loss • Scotomata • Hemianopia / quadrantinopia • Altitudinal field loss • Disturbed • Photopsia • Teichopsia • Diplopia 3. Hearing • Deafness • Tinnitus • Vertigo 4. Smell • Anosmia /dysosmia 5. Taste • Ageusia / dysgeusia (Cognition) Motor - Limbs • Weakness • Wasting • Fasciculation • Ataxia / clumsiness • Loss of dexterity • Hypokinesia & bradykinesia • Apraxia Neuromuscular / Muscular • Neuromuscular • eg Myasthenia Gravis • Myopathies • • • • Polymyositis Muscular dystrophies Mitochondrial disorders Endocrine myopathies (Vit D deficiency, hypothyroidism) • Proximal girdle weakness • Facial weakness • Neck & truncal weakness • Ptosis • Bulbar weakness • Wasting, if longstanding eg dystrophies Peripheral Nerve Disorders (Neuropathies) • Metabolic • B12 deficiency, diabetes • Toxic • Alcohol, drugs, Heavy metals • Inflammatory / infective • CIDP, vasculitis, leprosy, Lyme • Paraneoplastic • Genetic • Charcot Marie Tooth Lower Motor Neuron Signs • Wasting (amyotrophy) • Fasciculation • Hypo-reflexia • Hypotonia Nerve Root Disorders (Radiculopathies) • Degenerative • Spondylotic disease of the spine • Inflammatory / infective • Lyme • Autoimmune eg CIDP, vasculitis • Neoplastic • Neurofibromas • Meningeal carcinomatosis Dermatomes & Myotomes Disorders of The Plexi (Plexopathies) • Neoplastic • Breast cancer, bowel cancer • Inflammatory • Brachial Neuritis, CIDP • Vascular • Esp Lumbo-scaral plexus in diabetes Cortico-Spinal & Spinal Motor Neurons Upper Motor Neuron Signs • Spastic posture • Spastic tone (acute: flaccid) • Clonus • Hyper-reflexia • Babinski sign • Weakness, especially of: • • • • • hip flexion ankle dorsiflexion shoulder abduction elbow & wrist extension Finger abduction • Slowness of movements • Loss of Dexterity Cerebellar Input to Motor Circuits The Basal Ganglia Input to Motor Circuitry Executive, Pre-Motor & Motor Cortical Areas Gait & Posture • Spastic • Hemiplelgic • Diplegic • Ataxic • High-stepping • Waddling –Trendelenburg • Shuffling Romberg’s Sign • “Lasst man ihn in aufrechter Stellung die Augen schlissen, so gant er sofart an zu schwanken und zu taumelin” Romberg, MH Lehrbuch Nervenkrankheiten des Menschen 2 Vol II P 185, Aufl Berlin, Dunker 1851 • “If one lets him close his eyes standing, he immediately begins to sway and stumble” [patient with locomotor ataxia] Autonomic Sensory • Numbness (superficial sensory loss) • Akinaesthesia (propioceptive loss) • Paraesthesia • Allodynia / hyperpathia (altered pain) • Pain Sensory Pathway s Dermatomes & Myotomes Dermatom es – The Big Picture Arm Dermatomes Radicular Pain - Arm Leg Dermatomes Radicular Pain - Leg Cauda Equina Syndrome Key Messages • Cauda Equina syndrome is a sacral sensory & sphincter syndrome • If weakness occurs, it often only affects ankle and toe plantar flexion (S1/S2) with accompanying loss of ankle reflexes • It may be painless • Decompression undertaken later than 48 hours after clinical presentation yields very poor results • Litigation is common Sacral Dermatomes Spinal Pathways Spinal Cord Compression Anatomy • Spinal cord is shorter than spinal canal • ends at L1 / L2 interspace • Cervical spine: cord levels correspond to vertebrae • Thoracic spine: the cord level (clinical) lower than vertebral level • T12/L1 disc will compress the conus (sacral cord segments) T10/11 Cord compression in breast cacer Cord Compression Examination • High cervical spine compression • • • • Clumsy slow fingers Quadriplegia Respiratory problems Bladder & bowel dysfunction • Thoracic spine disease • Paraplegia • Sensory level • Bladder & bowel dysfunction • Traps for the unwary • Triple flexion response to pain • Gait ataxia may be the only feature High Cervical Cord Compression: Rheumatoid Peri-Odontoid Pannus Glove & Stocking Distribution Sensory Loss Sensory Examination of the Upper Limb • Sensory fibres from the medial & lateral forearm do not travel in the ulnar and median nerves • Sensory splitting of fingers is characteristic of median & ulnar lesions • Root lesions rarely produce dense sensory loss • CNS sensory disturbances are poorly demarcated Speech • Dysphonia/ hypophonia • Dysarthria • Cerebellar • Irregular volume and timing • Slurred • Bulbar (LMN) • Floppy • Nasal speech • Pseudobulbar (UMN) • Slow, strained, • Low-pitch • Parkinsonian • Mumbled • Quiet (hypophonic) • Slurred & festinating • Look for: • • • • Drooling (UMN> LMN) Brisk jaw jerk (UMN) Ptosis – Neuromuscular, myopathy or Guillain-Barre Strabismus - neuromuscular • Dysphasia • Broca • Wernicke etc Vision • Loss • Scotomata • Hemianopia / quadrantinopia • Altitudinal field loss • Disturbed • Photopsia • Teichopsia • Diplopia Teichopsia (Fortification Spectra) & Scintillating Scotomata Ophthalmoscopy Normal Papilloedema Optic Atrophy Where is the lesion? Inferior Optic Radiation Altitudinal Defect Central Scotomata Optic Neuropathy (ethambutol) Arcuate Scotomata Retinal nerve bundle eg glaucoma, optic disc drusen, ischaemic optic neuropathy, optic neuritis. Domains of Deficit Motor • Limbs • • • • • • Weakness Wasting / Fasciculation Ataxia / clumsiness Loss of dexterity Hypokinesia & bradykinesia Apraxia • Gait & Posture • • • • • Spasticity Ataxia High-stepping Waddling Shuffling • Speech • Dysphonia • Dysarthria • Dysphasia • Swallowing • Dysphagia • Nasal regurgitation • Autonomic (motor & sensory) • • • • Hypotension Gastroparesis / constipation Bladder / sexual function Pupil abnormalities Sensory 1. Sensory • • • • Numbness (superficial sensory loss) Akinaesthesia (propioceptive loss) Paraesthesia Allodynia / hyperpathia (altered pain) 2. Vision • Loss • Scotomata • Hemianopia / quadrantinopia • Altitudinal field loss • Disturbed • Photopsia • Teichopsia • Diplopia 3. Hearing • Deafness • Tinnitus • Vertigo 4. Smell • Anosmia /dysosmia 5. Taste • Ageusia / dysgeusia (Cognition) • • • Examination of Functional Disorders Weakness / paralysis • Hoover’s sign – demonstration of ‘can do, but not trying’ • • • • • Tilt sign “Collapsing weakness” (variable effort) “Unintentional Strength” Finger resistance No effort when resistance removed 1. Extension of the weak leg appears absent or weak (but in view of 2. below, ‘can’t be trying’) 2. Flexion of the good leg, demonstrates good power of extensors in the ‘weak’ leg (‘can do’) 3. Flexion of the weak leg, not accompanied by extension of the good leg (‘not trying’) Balance & Gait • Athletic ataxia Sensory & Pain • Non-dermatomal (caution CNS sensory loss) 1 and 2