Neurology (Stroke, epilepsy, degenerative brain disease) Flashcards
Describe the complete organizational structure of the nervous system
1) Central Nervous System (CNS) – brain and spinal cord, functioning as the “control center”;
2) Peripheral Nervous System (PNS) – nerves and cells in the periphery that detect and enact changes in internal/external environment, which is further divided into Autonomic (involuntary: sympathetic/parasympathetic) and Somatic (voluntary) components.
Name the four major regions of the brain and their respective functions.
1) Cerebrum (organized into lobes) – higher neurological functions such as memory, language, emotion, and consciousness
2) Cerebellum – balance, posture, and coordination
3) Diencephalon (thalamus + hypothalamus) – perception, temperature regulation, emotions, memory, and endocrine functions
4) Brain stem (midbrain, pons, medulla oblongata) – breathing, blood pressure, heart rate, and cranial nerves III-XII.
What are the three primary functions of the spinal cord?
1) Send motor commands from brain to periphery (muscles, glands, organs)
2) Send sensory information from periphery to brain (touch, pain, temperature, pressure)
3) Coordinate reflexes.
Differentiate between a seizure and epilepsy
A seizure is a transient episode of abnormal/excessive electrical activity in the brain resulting in signs or symptoms, with a broad differential diagnosis.
Epilepsy is a chronic condition where there is a tendency to have seizures, often diagnosed in childhood
List all the causes of epilepsy
1) Idiopathic (two thirds of cases)
2) Following stroke
3) Brain tumor
4) Following head injury
5) Following brain/meningeal infection
6) Drug/alcohol abuse.
Compare and contrast generalized and focal seizures, including the subtypes of motor seizures.
Generalized seizures affect both hemispheres and involve loss of awareness.
Focal seizures affect one area and may or may not involve awareness.
Motor seizures include:
Tonic (increase in muscle tone)
Atonic (“drop attack,” loss of muscle tone),
Clonic (repeated stiffening and relaxing of a muscle)
Myoclonic (brief muscle jerking).
Describe the four phases of a tonic-clonic seizure in chronological order with their characteristics.
1) Aura – sensory symptoms, emotional changes, dizziness, déjà vu
2) Tonic phase – muscles stiffen, loss of consciousness, tongue biting common, cry, incontinence, may hold breath
3) Clonic phase – jerking of arms/legs
4) Post-ictal phase – sleepy, confused, irritable.
What are the key characteristics of an absence seizure?
An absence seizure involves loss of consciousness, patient appears blank/unresponsive (like “day dreaming”), and typically lasts up to 15 seconds.
List the diagnostic approaches for epilepsy.
1) Eyewitness history/video
2) First-seizure clinic
3) Electroencephalogram (EEG)
4) MRI brain (to rule out structural causes).
Name the anti-convulsant medications used for different types of seizures and briefly explain how they work.
For tonic-clonic seizures: sodium valproate, lamotrigine, levetiracetam
For absence seizures: ethosuximide.
Less commonly used medications include carbamazepine, phenytoin, and topiramate. These medications work in various ways to reduce excitation or enhance inhibition of neurons at synapses, affecting GABA, sodium, glutamate, and calcium pathways.
Define status epilepticus and outline the emergency management protocol in a dental practice.
Status epilepticus is a prolonged convulsive seizure lasting 5 minutes or longer, or recurrent seizures without recovery in between. It is a medical emergency.
In a dental practice, management includes:
1) Assess the patient
2) Do not try to restrain convulsive movements
3) Ensure the patient is not at risk from injury
4) Secure the patient’s airway
5) Administer oxygen if able
6) Administer 10 mg midazolam (2 ml oromucosal solution, 5 mg/ml) topically into the buccal cavity
7) After convulsive movements have subsided, place the patient in the recovery position and check the airway.
What are the three main dental implications of epilepsy?
1) Emergency management of status epilepticus in the dental chair
2) Oral/facial injury (dental trauma, tongue biting)
3) Medication side effects (phenytoin causing gingival hyperplasia).
Provide the complete definition of stroke and differentiate between ischemic and hemorrhagic stroke types with their relative frequencies.
Stroke is “an acute neurological deficit lasting more than 24 hours and caused by cerebrovascular etiology.”
Ischemic stroke (85% of cases) involves vascular occlusion from thrombus/embolus
Hemorrhagic stroke (15% of cases) involves vascular rupture
Both result in neurological symptoms that vary depending on the brain territory affected.
Compare and contrast the risk factors for ischemic versus hemorrhagic stroke
Ischemic stroke risk factors: atrial fibrillation, carotid artery stenosis, hypertension, diabetes, raised cholesterol, family history, smoking, obesity, vasculitis, thrombophilia, and combined contraceptive pill
Hemorrhagic stroke risk factors: hypertension, aneurysm, arteriovenous malformation (AVM), and being anticoagulated.
Explain the FAST screening tool for stroke and list additional clinical features not included in FAST.
FAST:
F – Face (palsy)
A – Arm (weakness)
S – Speech (disturbance)
T – Time (act fast and call 999)
Additional clinical features include: visual field defects, sensory loss, ataxia/vertigo, swallowing difficulty, and loss of consciousness.
Outline the diagnostic and immediate management approaches for acute stroke.
Diagnosis:
1) CT head (urgent – to exclude a bleed); 2) MRI scan.
Immediate management:
1) Aspirin 300mg (after bleed is excluded); 2) Thrombolysis/thrombectomy; 3)
Rehabilitation;
4) Secondary prevention.
Compare thrombolysis and thrombectomy as treatments for stroke, including their time windows.
Thrombolysis: “Clot-busting drug” administered intravenously within 4.5 hours of symptom onset.
Thrombectomy: Physical clot retrieval performed within 24 hours of symptom onset.
List all secondary prevention strategies for stroke.
antiplatelet medication (clopidogrel for ischemic stroke)
blood pressure control (antihypertensives)
cholesterol-lowering medication (atorvastatin)
exercise
weight loss
smoking cessation
alcohol reduction.
Define Transient Ischemic Attack (TIA), list its symptoms, and describe its management.
TIA is “a transient episode of neurologic dysfunction caused by focal brain ischemia, without acute infarction” – a brief period of neurological deficit due to a vascular cause, typically lasting less than an hour. Symptoms include limb or facial weakness, speech disturbance, and partial visual loss. It is often referred to as a “mini stroke” and is managed similar to acute stroke with urgent specialist assessment
List all dental implications of stroke mentioned in the lecture.
Maintaining oral hygiene challenges due to loss of dexterity
Facial palsy (with forehead sparing*)
Dysphagia (impaired swallow, sialorrhea); Communication barriers (dysphasia/dysarthria)
Secondary prevention medications (antiplatelets causing increased bleeding risk).
Define multiple sclerosis, including its pathophysiology, demographic characteristics, and general presentation.
Multiple sclerosis is a chronic and progressive autoimmune condition involving demyelination in the central nervous system, where the immune system attacks the myelin sheath of neurons, affecting electrical signal transmission. Onset is typically before 40 years of age with a 3:1 female to male ratio. Clinical features vary based on which neurological areas are affected.
List all risk factors for multiple sclerosis mentioned in the lecture.
Risk factors include: genetics, low vitamin D, Epstein-Barr virus exposure, smoking, and latitude (distance from the equator).
Describe all potential clinical features of multiple sclerosis, noting their distribution pattern.
Clinical features are multisystem and can affect the body from “top-to-toe,” including
visual disturbances (optic neuritis)
facial pain (trigeminal neuralgia)
dysarthria
ataxia
limb weakness
spasticity
sensory disturbances
fatigue
bladder/bowel dysfunction
sexual dysfunction
cognitive impairment
mood disorders.
Name and describe the four different disease course patterns in multiple sclerosis.
Relapsing-remitting (most common): periods of relapse with new symptoms followed by periods of remission.
Primary progressive: steady worsening of neurologic functioning without periods of remission.
Secondary progressive: initial relapsing-remitting pattern that transitions to progressive deterioration.
Progressive relapsing: progressive disease from onset with acute relapses with or without recovery.
Outline the diagnostic and management approaches for multiple sclerosis.
Diagnosis primarily through MRI scan showing demyelination.
Management (multidisciplinary team): steroids for acute flares; disease-modifying drugs for long-term remission; medications for specific symptoms like neuropathic pain, urinary incontinence, and spasticity; physiotherapy and occupational therapy.
Define motor neurone disease, including its pathophysiology, prognosis, and demographic characteristics.
Motor neurone disease comprises a variety of specific diseases affecting the motor neurons, characterized by degeneration of upper and lower motor neurons while sensory neurons remain unaffected. It is rapidly progressive and eventually fatal (typically from respiratory failure or pneumonia). Onset is typically after 50 years of age, affecting predominantly males.
List all clinical features of motor neurone disease mentioned in the lecture.
Clinical features include: spasms, tongue fasciculations, muscle wasting, slurred speech, and weakness progressing to significant impairment.
Outline the management approaches for motor neurone disease.
feeding tube (PEG) for nutrition anticholinergic drugs/botulinum toxin for sialorrhea
respiratory support
end-of-life care planning.
List all dental implications of motor neurone disease
access challenges (timing, wheelchair access, whether to see in wheelchair or transfer to dental chair)
positioning concerns (not lying flat due to weak respiratory muscles and aspiration risk)
need for good quality oral suctioning
fatigue management
use of bite blocks
oral hygiene challenges due to decreased dexterity (requiring modified devices)
management of sialorrhea
communication barriers.
Define Parkinson’s disease, including its pathophysiology and prevalence.
Parkinson’s disease is a progressive neurodegenerative condition resulting in motor and non-motor symptoms due to degeneration of dopaminergic neurons in the substantia nigra (part of the basal ganglia). It is diagnosed in 1% of the population over 65 years of age.
Differentiate between motor and non-motor clinical features of Parkinson’s disease.
Motor features include: bradykinesia
rigidity
resting tremor
“shuffling” gait
reduced arm swing
forward tilt
hypomimia (decreased facial expression, “mask-like”)
micrographia (smaller handwriting), dysarthria (slurring of speech)
hypophonia (softer, “breathy” voice)
Non-motor features include: insomnia
cognitive impairment
depression
psychiatric features (hallucinations, delusions)
impaired sense of smell.
Outline the diagnostic and management approaches for Parkinson’s disease
Diagnosis is made through specialist clinical assessment.
Management includes:
- replacement of dopamine with levodopa (synthetic dopamine) as the mainstay treatment, often as co-beneldopa (levodopa with enzyme inhibitor to prevent breakdown in the body before reaching the brain)
- physiotherapy and occupational therapy
- deep brain stimulation (implanting electrodes in the brain to deliver electrical impulses that disrupt abnormal brain activity).
List all dental implications of Parkinson’s disease
Dental implications include:
facial dyskinesia (side effect of levodopa medication causing involuntary movement)
dexterity issues affecting oral hygiene; “on/off phenomenon” with medication requiring careful appointment scheduling; aspiration risk
dry mouth (side effect of levodopa and polypharmacy) affecting denture stability
challenges due to rigid orofacial musculature, dry mouth, and orofacial dyskinesia.
