• Astrocytes = control the environment and form the blood–brain barrier. • Microglial cells = blood-derived mononuclear macrophages. • Oligodendrocytes = produce myelin sheath in the CNS • Schwann cells = produce myelin sheath in the PNS. • Between the brain and the skull are 3 meninges = dura mater, arachnoid and pia mater. • The subarachnoid space is filled with CSF. • Sensory cell bodies are situated in the dorsal root ganglia. • The motor cell bodies are in the ant. horns of the spinal cord The onset, duration and pattern of symptoms over time often provide diagnostic clues: for example, in assessing headache or vertigo. • Headache with nausea, vomiting, photophobia +/- phonophobia = migraine • Headache with neck stiffness, fever and rash = meningitis • Headache is the most common neurological symptom and may be either primary or secondary to other pathology. • Recurrent headache, usually unilateral. • Evolves over 30min-2hrs, lasting up to 72hrs. • It is classified into classic (with aura) and common (without aura). • Ass. with nausea/vomiting, photophobia/phonophobia. • Orbital/retro-orbital; always same side during cluster, may switch sides between clusters. • Abrupt onset, attacks last up to 2hrs. Recurrent attacks 1-4x within 24hrs, lasting weeks to months. • Awakes the patient from sleep • Autonomic features (conjunctival injection, tearing, nasal stuffiness, ptosis, miosis, agitation). • During the attack the patient keep pacing around the room in an agitated state, or even head banging. • Abrupt onset, lasting very briefly (seconds or less). • Can be felt anywhere. • Can be felt anywhere. • Common in patients with migraine. Ass. with neck stiffness, fever, rash, signs of raised intracranial pressure and false localizing signs, meningism. Abrupt onset, maybe fatal at onset, ass. with nausea, vomiting, reduced consciousness, false localizing signs, 3rd nerve palsy In patients >55yrs, presents with jaw pain on chewing, visual symptoms, and tender temporal arteries, elevated ESR and CRP • Stimulation of PNS due to pain, emotion or illness or when forced to stand in warm environment leading to vasodilation and bradycardia. • Preceded by light-headedness, vision dimming, tinnitus, and nausea. • MCC of transient loss of consciousness; • Lasts 1-2 minutes. due to inadequate cerebral perfusion. • It causes pale or grey skin and maybe associated with myoclonic jerks. • Maybe due to: If kept flat, recovery is rapid. • With no previous alarm, triggered with exercise. • Causes: HCM, severe AS or arrhythmia. 1- Drugs (l-dopa or anti-HTN drugs). 2- Autonomic diseases (DM). 3- In people >65 years. 4- Hypovolemia. 1- Tonic phase: Early loss of consciousness ass. with body stiffening. 2- Clonic Phase: Rhythmical jerking increasing in intensity and subsiding over 0.5–2min. 3- Postictal phase: Period of unresponsiveness, heavy breathing, appearing deeply a sleep and finally confusion as the patient re-orientates. Caused by paroxysmal electrical discharges, • Simple (consciousness is preserved) or complex (impaired conciousness). can be: • Characterized by whichever part of the brain is involved. example: 1- Frontal lobe seizures = focal motor seizure. 2- Temporal lobe seizures = autonomic and/or psychic symptoms, ass. 2- Temporal lobe seizures = autonomic and/or psychic symptoms, ass. with automatisms (lip smacking or swallowing). • Common, often more frequent than epilepsy, sometimes occurring multiple times in a day, and may last considerably longer, with symptoms waxing and waning. • Other features include asynchronous movements, pelvic thrusts, side-to-side rather than flexion/extension movements and absence of postictal confusion. • A stroke is a focal neurological deficit of rapid onset that is due to a vascular cause, can be ischemic or hemorrhagic. • TIA is the same but symptoms resolve within 24hrs. • 80% of strokes are ischemic. Hemorrhagic stroke is much more frequent in Asian populations. We do brain CT w/o contrast to differentiate b/w them. • Factors in the history or examination that increase the likelihood of hemorrhage rather than ischemia include use of anticoagulation, headache, vomiting, seizures and early reduced consciousness. • Very rare; present with an abrupt onset, depending on the level of spinal cord affected. • The ant. spinal artery syndrome is most common and causes loss of motor function and pain/temp. sensation with relative sparing of joint position and vibration sensation below the level of the lesion (sparing dorsal column). • Recurrent ‘dizzy spells’ in 30% of those >65YO. • Causes = postural hypotension, cerebrovascular disease, cardiac arrhythmia or hyperventilation induced by anxiety and panic. • BPPV= Recurrent episodes of vertigo lasting a few seconds, increased when sleeping on the affected side or with movement. • Ménière’s disease = Vertigo lasting minutes or hours (ass. with hearing Vertigo is the illusion of movement loss, tinnitus, nausea and vomiting). indicating a problem in the vestibular apparatus or, less commonly, the brain. • Migrainous vertigo (with or without headache) • Stroke • Multiple sclerosis • Neurological Sx that are not due to disease are called ‘functional’ but other terms include psychogenic, hysterical, somatisation or conversion disorders. • Sx include: blindness, tremor, weakness and collapsing attacks, with fatigue, lethargy, pain, anxiety, etc. A history of previous visual loss in someone presenting with numbness suggests multiple sclerosis A history of previous visual loss in someone presenting with numbness suggests multiple sclerosis • Phenytoin toxicity = ataxia • Excessive intake of simple analgesia = medication overuse headache • Cocaine = provoking convulsions • Single-gene defects = in myotonic dystrophy or Huntington’s disease. • Polygenic influences = in multiple sclerosis or migraine. • Charcot–Marie–Tooth disease may be AD, AR or X-linked. • Mitochondria DNA abnormalities = diabetes, short stature, deafness, migraine or epilepsy. • Parkinson’s or motor neuron disease, may be either due to single-gene disorders or sporadic. • Alcohol is the most common toxin and damages both the CNS (ataxia, seizures, dementia) and the PNS (neuropathy). Alcoholism may cause vitamin deficiency. • Vegetarians may be susceptible to vitamin B12 deficiency. Nitrous oxide inhalation causes subacute combined degeneration of the cord due to vit. B12 pathway dysfunction. • A travel history may give clues to the underlying diagnosis, such as Lyme disease (facial palsy), neurocysticercosis (brain lesions and epilepsy) or malaria (coma). • Lead exposure = motor neuropathy. • Manganese exposure = Parkinsonism. Note: the ex. sequence for OSCE purposes was provided by the doctors; you can ignore the ex. attached figures here and consider it only for understanding of the OSCE steps maneuvers • Facial expression & Speech • Gait & Posture • Involuntary movements • General demeanor Dependent on the integrity of RAS, which extends from the brainstem to the thalamus, and describes how awake a person is. Depends on the cerebral cortex, thalamus and their connections describing how aware the person is, • Meningism (inflammation of the meninges) can lead to increased resistance to passive flexion of the neck (neck stiffness) or the extended leg (Kernig’s sign). Patients may lie with flexed hips to ease their symptoms. • Meningism suggests infection (meningitis) or subarachnoid hemorrhage, but can occur with non-neurological infections (UTI or pneumonia). Increased resistance to passive flexion of the neck Flexion of the knees in response to neck flexion Increased resistance to passive extension of the leg Bilateral UMN lesion of CNs 9, 10, 11 and 12. Slow, harsh speech with a contracted, spastic tongue, brisk jaw jerk, emotional lability and difficulty pronouncing consonants Bilateral LMN lesion of CNs 9, 10, 11 and 12. • Weakness of the tongue = difficulty with lingual sounds. Slurred speech caused by • Palatal weakness = nasal quality to the speech. articulation problems due to a motor deficit, causes include: Slow and slurred, similar to alcohol intoxication. Fatiguing speech becoming increasing nasal, and may disappear altogether. Dysarthria, dysphonia, with a low-volume, monotonous voice, words running into each other (festination of speech), and marked stuttering / hesitation. Usually results from either vocal cord pathology (laryngitis), or damage to the recurrent laryngeal nerve leading to a 'bovine' cough. Results from damage to Broca’s area, characterised by reduced verbal output with non-fluent speech and errors of grammar and syntax, however, comprehension is intact. Due to dysfunction in Wernicke’s area. There is poor comprehension, and although speech is fluent, it may be meaningless and contain paraphasias and neologisms. Abnormalities of speech production and/or understanding. May also involve other It is a combination of expressive and receptive difficulties language symptoms, e.g. writing and reading caused by involvement of both areas. unlike dysarthria and dysphonia. Types include: • Dominant parietal lobe lesions affecting the supramarginal gyrus may cause dyslexia (difficulty comprehending written language), dyscalculia (problems with simple addition and subtraction) and dysgraphia (impairment of writing). • Gerstmann’s syndrome is the combination of dysgraphia, dyscalculia, finger agnosia (inability to recognise the fingers) and inability to distinguish left from right. It localizes to the left parietal lobe (angular gyrus). • The posterior part of the frontal