NEUROLOGY REVIEW James K. Rustad, M.D. Copyright © 2010. All Rights Reserved. Lecture Outline Neuroanatomy Review Neurotransmitters: Dopamine, Norepinephrine, Serotonin Pain: Peripheral Nerve Fibers, Opiate Receptor Subtypes and Neuropathic Pain Syndromes Headaches (Tension, Migraine, and Cluster Headaches) Brain Hemorrhages (Subdural, Epidural and Subarachnoid Hemorrhages) Lecture Outline Dementias: Alzheimer’s, CJD, Lewy Body, Pick’s, NPH, SSPE Neuropathology “power review”: Parkinson’s, Huntington’s, Duchenne’s, ALS, Guillian Barre, Myasthenia Gravis, Multiple Sclerosis, Seizure Disorder, and Brown-Sequard Syndrome. Stroke Lesion Localization Aphasias Neuroanatomy Review Frontal Lobe: Remember stimulation drives eyes contralateral and destruction induces ipsilateral eye movement. Prefrontal Region - Frontal lobe anterior to motor strip contains executive and inhibitory centers. Parietal Lobe: Stereognosis, two-point discrimination, visual association area (perception of visual symbols). Angular Gyrus (Gerstmann’s syndrome). Occipital lobe: Visual cortex. Temporal lobe: Wernicke’s area. Mesial surface is origin of most partial complex seizures. Neuroanatomy Review (continued) Basal Ganglia = Caudate nucleus, Putamen, Globus Pallidus, Subthalamic Nucleus, Substantia Nigra. Striatum = caudate nucleus and putamen. Lenticular Nuclei = globus pallidus and putamen. Nigrostriatal tract (substantia nigra to striatum). Dopamine Metabolism Steps Phenylalanine Phenylalanine Hydroxylase Tyrosine Tyrosine Hydroxylase (ratelimiting) DOPA DOPA Decarboxylase Dopamine Dopamine Beta Hydroxylase Epinephrine Phenylamine NMethyltransferase Norepinephrine Serotonin Synthesis Tryptophan Converted by: Tryptophan Hydroxylase 5-hydroxytryptophan Converted by: Amino acid Decarboxylase Serotonin Breaks down to 5-HIAA (5-Hydroxyindoleacetic acid) Pain Peripheral Nerve Fibers, Opiate Receptor Subtypes and Neuropathic Pain Syndromes Peripheral Nerve Fibers Type C fibers A-delta fibers Size Small Large Myelin No Yes Conduction Velocity Slow Fast Character Dull, aching Sharp, brief Example Pancreatic cancer Burn Opiate Receptor Subtypes Receptor Action Mu Analgesia, respiratory depression, constipation, miosis (pupillary constriction), euphoria Kappa Analgesia, dysphoria, disorientation/depersonalization Delta analgesia Neuropathic Pain Syndromes Mononeuropathy: Carpal tunnel syndrome Polyneuropathy: Diabetic, Alcoholic Post-herpetic neuralgia Neuropathic Pain Syndromes Complex Regional Pain Syndrome Type I (Reflex Sympathetic Dystrophy) Initial noxious event involving distal extremity, pain disproportionate to injury, not limited to single nerve distribution. Associated with edema, changes in skin blood flow. Neuropathic Pain Syndromes Complex Regional Pain Syndrome Type 2 (Causalgia) Sequela of injury to nerve or major branch (esp. median, sciatic, tibial, and ulnar nerves). Thalamic Pain: Dejerine-Roussy Syndrome Due to thalamic infarct or other lesion. Hemi-anesthesia followed by gradual return of sensory function and pain. Pain contra-lateral to lesion. Headaches Headaches Tension headache Dull, bilateral, band like, chronic in course and usually related to stress. Tx: NSAID, rule out Major Depression Migraine: at least five episodes of Episodic Headache lasting four to seventy two hours Any two of: Unilateral Throbbing Worsened by movement Moderate or Severe Any one of: Nausea or vomiting Photophobia and phonophobia Five Phases of Migraine Attack Phase I: Prodrome Phase II: Aura Phase III: Headache Phase IV: Headache Resolution Phase V: Postdrome Migraine Treatments Acute Non-specific: NSAIDS, Combination analgesics, Opioids, Antiemetics, Neuroleptics. Specific: Ergotamine, Dihydroergotamine, Triptans. Preventive Anticonvulsants (Divalproex, topirimate) Tricyclics Beta-Blockers Calcium Channel Blockers Cluster Headache M/F 6:1 Unilateral stabbing headache Ipsilateral lacrimation and nasal congestion with rhinorrhea Usually triggered by alcohol use. Treatment: 100% Oxygen (“Air Supply”) Cluster Headache Rare Disorder (0.1-0.4% of population) Age of onset 20’s-30’s Clinical features: Excruciatingly severe, retro-orbital pain. Radiates to temple, teeth, neck. Last 15-180 minutes. Ipsilateral autonomic features, pacing, nocturnal attacks often awaken them. Triggers: Alcohol, Nitroglycerin. Cycles usually occur spring and fall and last 4-12 weeks. Cluster Headaches Acute Oxygen 5-10 Liters Sumatriptan injection (FDA approved) Ergotamine Preventive Prednisone Verapamil Lithium (for chronic cluster headaches) Divalproex Brain Hemorrhages Subdural, Epidural and Subarachnoid Hemorrhages Subdural Hematoma Suspect in older patient with new-onset headache Follows head trauma Tearing of bridging veins Extra-axial mass causes focal findings Waxing and Waning mental status “Concave on CT” Epidural Hematoma Between bone and dura Associated skull fracture in 85% of adults Middle meningeal artery tear Brief LOC, initial lucid period then acute deterioration “Convex on CT” Subarachnoid Hemorrhage Cause: Rupture of aneurysm or AV malformation. Clinical feature: sudden onset of “worst headache of my life” Studies: CT scan. LP will show blood and Xanthochromia (yellow heme pigment) Tx: Clip aneurysm “Athena and Zeus” Subarachnoid Hemorrhage Occipito-nuchal Sentinel bleeds Most common cause? Trauma Dementias Alzheimer’s Disease Extracellular deposition of amyloid-beta protein, intracellular neurofibrillary tangles, and loss of neurons. CT: Atrophy, ventricular dilatation Treatment: CJD vs. AD CJD AD Course Six months (rapid) Insidious (years to decades) Physical findings Myoclonus EEG Periodic complexes, burstsuppression CSF 14-3-3 protein (>90%), some false + Pathology Spongiform changes Plaques and tangles Transmissibility Person to person and person to animal Non-transmissable Slowing of background Huey, Dewey and… …..Lewy Body Dementia 2nd commonest cause of degenerative dementia Progressive cognitive impairment Spontaneous onset Parkinson’s symptoms Extreme neuroleptic sensitivity, Sleep problems, V/H Pick’s disease Personality change Decline in function Poor social judgment Inappropriate Pathology: Prominent fronto-temporal atrophy, neuron cell inclusions, clustered cytoskeletal elements “NPH wouldn’t do that!” Triad: an imbalanced, wide-based walk or “shuffle,” urinary incontinence and MEMORY PROBLEMS. Dementia predominantly frontal lobe in nature, with apathy, dullness in thinking, and slight inattention. Memory problems are usually main problem, which can lead to the misdiagnosis of AD. Neil Patrick Harris, aka “Doogie Howser, MD” Normal Pressure Hydrocephalus Dementia Incontinence Gait apraxia (“magnetic gait”) Subacute Sclerosing Pancephalitis (SSPE) Dementia and myoclonus with onset in childhood Course usually rapid and fatal, may be aborted with antiviral drugs CSF has anti-measles antibodies, and EEG shows periodic or burst-suppression Cause probably measles or measles-like virus Neuropathology “power-review” Parkinson’s, Huntington’s, Duchenne’s, ALS, Guillian Barre, Myasthenia Gravis, Multiple Sclerosis, Seizure Disorder, and BrownSequard Syndrome. Parkinson’s Disease Cardinal Features Tremor: resting, “pillrolling,” coarse, 3-5 Hz. Rigidity: “cogwheel” Bradykinesia or akinesia Minor Features Festinating gait: small accelerating steps with decreased arm swing. Postural reflex abnormalities including a positive “pull test” Hypophonia, Micrographia Sleep Disturbances (partly iatrogenic from dopamine agonists) Huntington’s Disease Atrophy of cerebral cortex and head of caudate nuclei leads to compensatory enlargement of lateral ventricles (“bat-wing”). Excessive Cytosine-Adenine-Guanine (CAG) trinucleotide repeats (other illnesses with excessive trinucleotide repeats include: Myotonic dystrophy, Fragile X syndrome, many forms of Spinocerebellar degeneration). Duchenne’s Type Muscular Dystrophy Sex-linked recessive inheritance with onset in early childhood Caused by loss of muscle membrane protein, dystrophin Pseudohypertophy (especially in calves) Proximal weakness: requires arms to arise from chair or floor DTRs decreased except for Achilles reflexes (ankle) Elevated muscle enzymes: CPK, aldolase UMN vs. LMN Sign and Symptoms Upper Motor Neuron Lower Motor Neuron Reflexes Hyperactive Hypoactive Babinski sign Positive (dorsiflexion) Negative Muscle atrophy Absent Present Muscle tone Spasticity Flaccidity Fasciculation Absent Present Amyotrophic Lateral Sclerosis Combines UMN and LMN symptoms Asymmetric limb weakness = most common presentation. Limb fatigability, twitching, wasting, and stiffness. Bulbar onset (2nd most common type) features dysarthria and dysphagia. “Lou Gehrig’s disease” Clinical Case Scenario A patient develops progressive weakness two weeks after a viral infection. What is possible diagnosis and what tests would you order? Acute Idiopathic Polyneuropathy “Guillain Barre Syndrome” Guillain-Barre Symmetric weakness, usually beginning in the legs, and more marked proximally than distally. Some sensory complaints. Typical absence of deep tendon reflexes. May be marked autonomic dysfunction. Slow conduction velocity CSF shows increased protein concentration but normal cell count. Electrophysiology shows marked slowing of motor/sensory nerve conduction velocity (denervation and axonal loss) Guillain-Barre Treatment: Plasmapheresis or IV IG Myasthenia Gravis Insidious onset. Slowly progressive course. Diplopia, dysarthria, ptosis, extremity and generalized weakness not conforming to distribution of any single nerve. Pupillary responses not affected. Persistent activity of a muscle group leads to temporary increase of weakness > restoration of strength after brief rest. Myasthenia Gravis Edrophonium challenge test (screening) EMG Confirmatory: Ach receptor antibody test Tx: Neostigmine, Pyridostigmine (if poor response: Corticosteroid). Consider Thymectomy in all patients < 60 yr unless only extraocular weakness. Multiple Sclerosis Relapsing remitting symptoms Separated in space and time MRI: Multiple periventricular plaques in white matter. Oligoclonal bands in CSF. Internuclear ophthalmoplegia When the patient attempts to look to left, left eye turns with nystagmus (abducted eye) and right eye cannot turn to left (impaired adduction). Location of lesion: Medial longitudinal fasciculus. Young adults: MS most common cause Older patients: vascular diseases. Seizure Disorder Partial Seizures: originate in a focal region of a single hemisphere Simple Partial Seizures: no alteration of consciousness Secondary Generalization: spreads to both hemispheres Complex Partial Seizures: alteration of consciousness Brief Duration (i.e. 2-3 minutes); May have motionless staring or automatisms (involuntary motor behaviors) Generalized seizures: involve both cerebral hemispheres from the outset (1). Tonic: sudden muscular rigidity (extension or flexion) (2) Clonic: generalized rhythmic jerking of muscles, no initial tonic phase (3) Generalized tonic clonic (may feature epileptic cry, apnea/cyanosis). Ictal activity 1-2 min; Post-ictal: incontinence, flaccidity, gradually return to normal consciousness. Disoriented, headache, sore mouth (oral trauma, muscular ache) (4). Atonic Seizure: brief loss of muscle tone (5). Absence ("petit mal") a few seconds of staring/blank look/unresponsive (6). Myoclonic: localized or widespread: non-rhythmic rapid jerking movements of muscles Brown-Sequard Syndrome Contra: loss of P and T, Ipsi: loss of vib./joint position, paralysis, hyperreflexia, Babinski CSF in Meningitis Diagnosis Cells Glucose (mg/dl) Protein (mg/dl) Opening Pressure Normal 0-5 lymphocyte 45-85 15-45 70-180 Aseptic,viral 25-2000, mostly lymphocytes NORMAL High > 50 Slight elevation Bacterial 200-20,000 Polymorphs, neutrophils Low <45 High >50 Markedly high Tuberculosis 100-1000 lymphocytes Low <45 High > 50 Moderate Elevation LOCALIZATION OF STROKES The Circle of “whatchu talkin’ bout” Willis? Anterior Cerebral Artery Profound lower extremity weakness (contralateral) Stroke may result in paralysis/sensory loss in contralateral leg and foot. Middle Cerebral Artery Profound upper extremity weakness (contralateral). Contralateral hemiplegia, hemisensory loss and homonymous hemianopia, eyes deviated to side of lesion. Apraxia/neglect. If left lobe involved: Global aphasia. Posterior Cerebral Artery Contralateral homonymous hemianopia, with macular sparing. Prosopagnosia (inability to recognize faces) Vertebrobasilar Artery Vertigo Nausea and vomiting “Drop Attack” Vertical Nystagmus Dysarthria/dystonia Ataxia Labile Blood Pressure Posterior inferior cerebellar artery Lateral Medullary or Wallenberg’s syndrome Sensory loss of the “FACE” 9 and 10 C.N. damage Limb ataxia Horner’s syndrome Spinothalamic sensory loss Pure Motor Stroke Weakness of face, arm, and leg on one side of body (without cognitive, sensory, visual abnormalities) favors presence of thrombotic stroke involving penetrating arteries or small intracranial hemorrhage. Gerstmann’s Syndrome Finger agnosia Left-right disorientation Agraphia Acalculia Dominant parietal lobe angular gyrus lesion (stroke or congenital abnormality). Associated with learning disabilities, right-sided paresis and hyperactive DTR’s. Category Non-fluent Aphasia Fluent Aphasia Previous terms (not synonymous) Expressive, Motor, Broca’s, Anterior Receptive, Sensory, Wenicke’s, Posterior Spontaneous Speech Output: Sparse < 50 WPM, single words Content: Nouns and Verbs primarily, Dysarthric, Telegraphic Output: Plentiful > 100 WPM, entire phrases, Paraphasias (incorrect words, clang associations, neologisms) Response to Tests Comprehension Preserved but Naming and Repeating impaired Comprehension Impaired (variable) and Naming and Repeating impaired Associated Deficits R-sided hemiparesis (arm > leg) Minimal hemiparesis, hemianopia, hemisensory loss Etiology CVAs, trauma, other focal lesions Focal lesions, sometimes frontotemporal dementia, AD, cerebral anoxia Location of Lesion Frontal lobe, especially L MCA Temporal or parietal lobe Variants of Fluent Aphasia Conduction Transcortical (Isolation) Abnormality Cannot repeat Can only repeat (echolalia), other functions variable Nature of Injury Disconnects arcuate fasciculus Isolates language arc from remainder of cortex Etiology Focal lesions Anoxia, CO poisoning, occasionally AD Location of lesion Posterior temporal lobe Area(s) surrounding perisylvian arc Any questions?