CNS Conditions, Signs, Causes And Differentials Flashcards by XXXXX XXXX

Q

Which structures can cause headache?

A

CSF-containing structures (ventricles, aqueducts)

Trigeminovascular system (neurones tha5 innervate the cerebral blood supply)

Meninges

Muscles of head

Nerves of head

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Q

What is a secondary headache?

A

A headache caused by an underlying pathology.

Examples:
Space occupying lesion
Intracranial HTN
Vasculitis (GCA)

(A primary headache has no underlying pathology)

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Q

Can you think of examples of a primary headache?

A

Migraine

Cluster headache

Tension headache

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Q

What is a chronic tension-type headache?

A

A band-like ache in head, neck or face.

Occurring for >15 days of every month

Occurring for more than 3 months

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Q

What are the symptoms of a tension-type headache? (SOCRATES)

A

Bilateral pain in head, face or neck
Unaffected by activities/daily routine
Pressing/tightening
Lasting for more than 30 minutes continuously
Mild/moderate severity

(NO associated symptoms)

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Q

What would you see on retinoscopy of a patient with papilloedema?

A

Enlarged optic disc (swollen with oedema)
Blurred edges of optic disc
Haemorrhagic changes around edges of optic disc

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Q

How will your visual field change if you have raised ICP?

A

Enlarged blind spot

2. Loss of peripheral field

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Q

What are two common causes of sixth nerve palsy?

A

Raised ICP (the palsy is a false localising sign)

2. Nerve infarct (from GCA)

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Q

What neurological pathologyphysiology is an ataxic gait indicative of?

A

Lesion in the posterior fossa

Ataxic - broad based and unsteady

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Q

Which systemic conditions cause increased risk of venous clots in the ventricular sinuses?

(They also cause a pink blanching rash)

A

Phospholipid antibody syndrome
Systemic lupus erythematosus
Vasculitis

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Q

What are the signs of raised intracranial pressure?

Hint:Start at brain, work downwards

A

Throbbing aching headache worse on recumbence (posture/Cranial BP-dependence)

Bilateral pain

Actively wakes patient during sleep

Respiratory depression and bradycardia

Decreased GCS

Nausea and vomiting

New onset seizures

Neuro-deficit

Pulse synchronous tinnitus

Transient vision loss on standing: blurring (postural)

Papilloedema

Valsalva manoeuvre and bending over precipitates it (BP-dependence)

High BP (to maintain cranial perfusion pressure)

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Q

Which four types of bacteria cause bacterial meningitis?

A

Listeria monocytogenes
Streptococcus pneumonia’s
Haemophillus influenza
Neisseria meningitides

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Q

Which viruses can cause viral meningitis and encephalitis?

A

Enterovirus
Herpes simplex
Varicella zoster
Cytomegalovirus
Epstein-Barr virus
Adenovirus

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Q

What is spondylodiscitis?

A

Bacterial infection of the vertebral disc (discitis) and intervertebral spaces (spondylitis)

Caused by:
Staphylococcus aureus
Streptococcus
Enterobactericae

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Q

What is the only fungus that causes meningitis?

A

Cryptococcus neoformans

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Q

Which neurological cause would give pronator drift?

A

With patient their eyes are closed and hands out, palm up:

Pronator drift = one or both hands turn over

Cause - pyramidal tract dysfunction

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Q

Which neurological cause would give a patient hemi-neglect?

A

Hemi-neglect = failure to be aware of objects to one side of a space

Cause - contralateral parietal lobe lesion

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Q

Which neurological cause would give a patient cerebellar drift?

A

With the patient closing their eyes and holding their hands out, palm up:

Cerebellar drift = arm drifts upward (flexion at shoulder)

Cause - unilateral cerebellar lesion

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Q

What are the causes of raised intracranial pressure?

A

Brain issue:

Cerebral oedema
Tumour
Haematoma
Abscess

CSF issue:

Obstruction
Decreased absorption
Increased production

Blood volume issue:

Increased serum CO2 (increases blood production)
Venous drainage obstruction
Hyperthermia (vasodilates the brain)

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Q

Why does the body increase arterial blood pressure when there is raised intracranial pressure?

A

This increase maintains the cerebral perfusion pressure, necessary in order to keep brain oxygenated.

CCP = BP - ICP

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Q

Which artery is most likely to be damaged in an extradural haematoma?

A

The middle meningeal artery

Extradural haematoma are most commonly arterial in origin, so they have a fast progression

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Q

A patient endures head trauma and develop an extradural haematoma:

what are the changes in consciousness after trauma?

A

Trauma occurs:

Cerebral concussion (initial loss of consciousness due to trauma)
Lucid period (fully conscious)
Consciousness progressively decreases (haematoma develops,

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Q

Why is a subdural haematoma slow in its progression?

A

A subdural haematoma is more often venous in origin, so it’s a slow ooze of blood within the cranium.

Latency period before presentation = weeks to months

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Q

What are the signs of a subdural haematoma?

A

Trauma occurs weeks-months before presentation.

Symptoms fluctuate. (Haematoma contracts and expands as osmotic effects change)

Headache.

Drowsiness.

Confusion.

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What is obscuration?

A transient greying out of something. e.g. vision

What are the signs of giant cell arteritis?

Scalp pain/tenderness Relative afferent pupillary defect (Regina can’t sense light so appears to dilate in a bright light) Altitudinal visual field defect (either upper or lower half of field is selectively affected) Jaw/tongue claudication on chewing Limb claudication Polymyalgia rheumatologica (joint pains) Loss of weight/cachexia Cranial nerve palsies May lead to total loss of vision

What are the signs of migraine? | Pain location, character, trigger, aura signs, aura duration, signs duration, sign frequency

Pain location: Unilateral or bilateral Pain quality: Pulsing (throbbing or banging in young people aged 12–17 years) Effect on daily living: Aggravated by, or causes avoidance of, routine activities of daily living Other symptoms: Photophobia, phonophobia (Unusual sensitivity to light and/or sound or nausea and/or vomiting) Aura symptoms can occur with or without headache and: - are fully reversible - develop over at least 5 minutes - last 5−60 minutes. Typical aura symptoms include: - visual symptoms such as flickering lights, spots or lines and/or partial loss of vision - sensory symptoms such as numbness and/or pins and needles - speech disturbance Duration of headache: 4–72 hours in adults 1–72 hours in young people aged 12–17 years Frequency of headache: Less than 15 days per month = episodic 15 days per month or more for more than 3 months = chronic

What are the signs of cluster headache? | Pain location, character, severity, signs duration, sign frequency

Location: Unilateral Character: Variable (can be anything) Severity: Severe ``` Local nasal, eye and face effects On the same side as the headache: - forehead and facial sweating - red and/or watery eye - swollen eyelid - constricted pupil and/or drooping eyelid - nasal congestion and/or runny nose ``` Duration: 15–180 minutes Episodic: - 1 every other day (up to 8 per day) - with remission more than 1 month in a 12 month period Chronic: - 1 every other day (up to 8 per day) - continuous remission period of less than 1 month in a 12-month period

Is a unilateral headache that is throbbing in character specific to migraine?

No, a cluster headache is unilateral and variable in character (could be throbbing) Expect: - Cluster headache to be more severe and have associated symptoms in the face, nose or eye on the same side - Migraine headache is moderately severe, and has associated photophobia, phonophobia and nausea, also possible aura (visual, sensory, speech)

What is an aura?

A visual, somatosensory, motor, speech or gastric disturbance that can precede or accompany migraine onset.

What are the types of visual aura that can accompany migraine?

Chaotic distortion Melting/jumbling of lines, dots and zigzags Scotomata (partial visual field loss) Scintillating scotomata (partial visual field loss with sparkling flashes) Hemianopia (50% visual field loss)

What is the somatosensory aura of migraine?

Parasthesiae (numbness)

What are the motor signs of aura in migraine?

Dysarthria Ataxia Opthalmoplegia Hemiparesis

What are the speech aura effects of migraine?

Dysphasia Paraphasia (jumbled words, nonsensical sentences)

Why are vomiting and nausea so common in migraine?

Gastric stasis often occurs as part of the aura, which contributes to nausea and vomiting

What fraction of people with migraine have aura?

20-30%

What is a menstrual-related migraine?

A migraine that occurs 2 days before or up to three days after menstruation begins, and occurs in 2/3 consecutive cycles.

What are the causes of migraine? | pathophysiological processes occurring

1. Cortical spreading depression (a slow depolarisation wave in the trigeminal nucleus caudalis causes sustained neuronal activity depression and changes in vascular calibre, causing pain) 2. Vasodilation and vasoconstriction 3. Failure of visual cortex inhibitory circuits 4. Trigeminal nerve pathology

What is the classic triad of symptoms associated with meningitis?

1. Headache 2. Stiff neck 3. Photophobia

What are the early signs of meningitis?

Headache or fever Abnormal skin colour (soles and palms are darker) Cold hands and feet Leg pains

What are the later signs of meningitis?

Neck stiffness Photophobia Kernig’s sign (can’t do knee extension on full hip extension) Non-blanching rash Decreased consciousness (or coma) Seizures

For a child presenting with rash and fever, what is the differential?

Meningitis until proven otherwise

Does meningitis generally present with GCS changes?

No. Symptoms are: headache, fever, rash, neck stiffness and photophobia GCS changes (e.g. confusion and seizure) indicate encephalitis (brain inflammation)

What are the symptoms of a cranial space occupying lesion?

``` 1.Signs of raised intracranial pressure: Headache N and V Vision blurring Papilloedema GCS changes HTN Bradycardia/Bradypnoea ``` 2. Impact on adjacent structures of the cortex: Sensory, motor, hormonal or autonomic dysfunction 3. Cortical/meningeal irritation: Seizures - generalised or focal Headache

What are the causes of space occupying lesion symptoms? | think VITAMIN E

``` Vascular: Extradural haemorrhage Subdural haemorrhage Subarachnoid haemorrhage Parenchyma haemorrhage ``` ``` Infection: Brain abscess Subdural empyema Parasite Granuloma ``` Tumours (primary or secondary, benign or malignant) -58% are malignant Anatomical: 1. Hydrocephalus - Obstruction = Tumours, cysts and intraventricular haemorrhage - Communicating = (dural venous sinuses are blocked) Meningitis and subarachnoid haemorrhage (Remember that the dural venous sinuses are outpockets of the subarachnoid space, piercing the arachnoid but not the dura mater) - Overproduction = choroid plexus papilloma 2. Cavernoma or vascular malformations in brain 3. Brain infarct: stroke

What are the two most common malignant brain tumours?

1. Glioblastoma multiforme (25% of all malignant brain tumours) 2. Anplastic astrocytoma (20%)

What is the commonest benign brain tumour?

Meningioma (arises from arachnoid cells)

What is a vestibular schwanoma?

AKA Acoustic neuroma A slow-growing benign tumour occurring in the nerve sheath of the vestibular nerve. Signs: Ipsilateral hearing problems Tinnitus - Affects CN 5,7,8,9,10,11 and 12

What is the pain of a tension headache like?

Bilateral Pressing or tight band No associated symptoms Lasts 30 minutes - continuous Unaffected by daily living activities Mild/moderate severity

A patient is pacing around, tapping his foot and looking agitated, are they more likely to have cluster headache or migraine?

Cluster headache Migraine are often made worse by moving. Cluster headaches make you feel restless and agitated

What is hypertensive encephalopathy?

The result of malignant, continuous hypertension in the cerebral vasculature. The brain arterioles lose their ability to regulate blood flow to the cerebral capillaries, fluid leaks out causing cerebral oedema and raised intracranial pressure.

What are the signs of hypertensive encephalopathy?

Many kinda of focal neurological signs: Dysphasia Muscle weakness Numbness Seizures Coma Paralysis Stupor

What are the triggers for migraine?

``` CHOCOLATE: Chocolate Hangover Orgasms Caffeine and cheese Oral contraceptives Lie ins Alcohol Travel Exercise ```

What is transient loss of consciousness? (TLOC)

TLOC is simply described as black outs, but also applies to fits, faints and funny turns. This includes vasovagal syncope, cardiogenic syncope, provoked seizures, unprovoked seizures, psychogenic non epileptic attacks and other aetiologies. The technical definition is: spontaneous loss of consciousness with complete recovery. Over half of all people will have LOC at some point in their life. Most commonly due to CARDIOGENIC SYNCOPE. It is unlike the alternative which is loss of consciousness without recovery.

When patients have seizures do they lose consciousness?

Not in every case, some retain awareness and some have awareness and retain partial consciousness.

What is the most common system of the body that causes transient loss of consciousness?

Cardiovascular

Is vasovagal syncope common if a person is lying down?

No, vasovagal syncope normally occurs when standing. Cardiogenic syncope is more common when sitting: Associated symptoms: palpitations, dizziness, sweating, light-headedness and clamminess.

When does a seizure occur? (In terms of excitation)

When excitation exceeds inhibition

What are the causes of transient loss of consciousness?

1. Vasovagal syncope: decreased BP precipiatated by long standing, shock, dehydration. 2. Cardiogenic syncope: decreased cardiac output due to arrhythmia or a obstructive cardiomyopathy. 3. Seizures: abnormal and excessive discharge of electricity within the brain A)Provoked seizure - alcohol excess/withdrawal, drug use (cocaine, ecstasy, amphetamines, opioids) B)Unprovoked seizure - epilepsy (repeated unprovoked seizures) 4. Psychogenic non-epileptic attack disorder: Loss of consciousness due to involuntary subconscious psychological mechanisms 5. Rare causes: Migranous events, vestibular disorders, cerebrovascular events (TIA) and sleep disorders.

What are the presyncopal (prodromal) symptoms that you may find in vasovagal syncope?

``` Presyncopal symptoms: light headedness dizziness visual blurring ringing in ears auditory distortion sweating feeling cold ``` Note: cardiogenic syncope doesn’t generally have prodromal symptoms, it’s just drop-dead kinda stuff

What are the pre-seizure symptoms?

Seizure symptoms: epigastric rising sensation abnormal taste/smells dejavu

Is shaking/jerking of the limbs exclusive to seizures?

No, jerking and twitching of the limbs can occur in both syncope and seizure.

What is the definition of syncope?

Loss of consciousness due to lack of cerebral blood supply.

What is the common motor activity seen in syncope?

``` Motor activity often occurs if they were upright beforehand or the LOC is prolonged: Twitching of the limbs Stiffening Jerking Tongue biting Incontinence ```

What are the common presyncopal symptoms that help distinguish it from seizures?

PPP:Position Provocation Prodrome Vasovagal = standing upright pain/dehydration/emotional shock/etc lightheadedness/auditory or visual disturbance etc And the duration of LOC is short

How do we distinguish epilepsy from non-epileptic attack disorder?

Epilepsy - we see evidence of abnormalities on electroenephalogram. Non epileptic attack disorder - no abnormalities detected.

What are the signs of non-epileptic attack disorder?

Gradual onset Prolonged duration Abrupt termination Accompanied by: closed eyes, rapid breathing, fluctuating motor activity, and episodes of motionless unresponsiveness.

What is epilepsy?

Epilepsy is a tendency to spontaneous, intermittent, abnormal electrical activity in part of the brain, manifesting as seizures. (Must be recurrent and unprovoked to be epilepsy) Epilepsy criteria, any of these will do: 1. Two or more unprovoked seizures more than 24 hours apart 2. One unprovoked seizure and a probability of further seizures (>60%) occurring over next 10 year 3. Diagnosis of an epilepsy syndrome Note: Epilepsy DOESN’T have to involve transient loss of consciousness!! Types: There are over forty types of epilepsy. Basic categories are: 1. Generalised (absence; tonic-clonic; myoclonic; atonic) 2. Focal with impaired consciousness 3. Focal without impaired consciousness 4. Combined generalised and focal 5. Unknown Classification of epileptic syndromes is separate to the classification of seizures, and is based on seizure type, age of onset, EEG findings, and other features such as family history.

What are the causes of epilepsy?

Epilepsy has a wide ranging set of aetiologies. Genetic - chromosomal and gene Structural - cortical developmental, vascular malformation, hippocampal sclerosis, hypoxic, ischemic, traumatic injury, tumours Metabolic Immune - antibody mediated Infectious Unknown

What is a seizure?

A seizure is a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Technical definition: A disruption in the normal balance between excitatory and inhibitory currents or neurotransmission in the brain resulting in hypersynchronous neuronal discharge. The signs and symptoms can be altered consciousness, sensory or motor. ``` Types: depends on onset Focal hemispheric Focal lobar Focal to bilateral General motor onset General non-motor onset ``` Focal seizure is also known as partial onset seizure.

In the context of seizures what are convulsions?

Convulsions are the motor signs of abnormal electrical discharges.

What are the major categories in to which seizure types can be differentiated?

In short: Focal with/without impairment of consciousness, focal transforming to general, General absence, general tonic-clonic, general myoclonic and general atonic Presentations: FOCAL One side affected (motor, sensory, autonomic etc) with or without affected consciousness Convulsions ``` Presentations: GENERAL Pausing during speech (non-motor) Limbs stiffen then jerk with lost consciousness Sudden jerking of limb(s) Floppy limb(s) ``` Focal seizures: (Originating within one hemisphere and often seen with underlying structural disease.) 1. Without impairment of consciousness Awareness is unimpaired, with focal motor/sensory/autonomic/psychic symptoms. No post-ictal symptoms. Awareness unimpaired. 2. With impairment of consciousness: Awareness is impaired—either at seizure onset or following a simple partial aura. 3. Evolving to a bilateral, convulsive seizure: A seizure that begins as focal and changes to a generalized seizure, which is Typically convulsive. Generalized seizures: (Rapidly engages the cortex, inducing simultaneous onset of widespread electrical discharge with no localizing features referable to a single hemisphere) 4. Absence seizures: Brief (≤10s) pauses, eg suddenly stops talking in mid-sen- tence, then carries on where left off. Presents in childhood. 5. Tonic–clonic seizures: Loss of consciousness. Limbs stiffen (tonic), then jerk (clonic). May have one without the other. Post-ictal confusion and drowsiness. 6. Myoclonic seizures: Sudden jerk of a limb, face, or trunk. The patient may be thrown suddenly to the ground, or have a violently disobedient limb. 7. Atonic (akinetic) seizures: Sudden loss of muscle tone causing a fall, no LOC. 8. Infantile spasms: (OHCS p206) Commonly associated with tuberous sclerosis.

What is clonus?

Jerking of a limb

What does tonic mean?

Tonic in the context of seizures means increased tone, meaning stiffness/stiffening.

What does ictal mean?

Ictal refers to a state or event such as stroke , seizure or headache. So the aura (warning signs: psychiatric, sensory, motor etc) phase of a seizure can be referred to as pre-ictal. During a seizure is referred to as the ictal period.

Where is a seizure likely localised in the cortex if the patient exhibits automatisms (complex motor phenomena with impaired awareness; primitive oral = lip smacking/chewing/swallowing or complex manual = fumbling/fiddling/grabbing)

Temporal lobe - but not motor features like posturing or pedalling movements of the legs, more like the memory centre, regression!

Where is a seizure likely localised in the cortex if the patient exhibits dysphasia?

Temporal lobe or frontal lobe

Where is a seizure likely localised in the cortex if the patient exhibits deja vu?

Temporal lobe

Where is a seizure likely localised in the cortex if the patient exhibits emotional disturbance (sudden terror, panic, anger or elation)?

Temporal lobe

Where is a seizure likely localised in the cortex if the patient exhibits hallucinations of smell, taste or sound?

Temporal lobe

Where is a seizure likely localised in the cortex if the patient exhibits delusional behaviour or bizarre associations?

Temporal lobe

Where is a seizure likely localised in the cortex if the patient exhibits posturing or pedalling movements of the legs?

Frontal lobe - motor cortex, contains the motor homunculus

Where is a seizure likely localised in the cortex if the patient exhibits motor arrest?

Frontal lobe - motor cortex, contains the motor homunculus

Where is a seizure likely localised in the cortex if the patient exhibits dysphasia or speech arrest?

Frontal cortex - both are motor functions, contains the motor homunculus

Where is a seizure likely localised in the cortex if the patient exhibits sensory disturbances like tingling, numbness or pain?

Parietal lobe - contains the sensory homunculus

Where is a seizure likely localised in the cortex if the patient exhibits visual symptoms like spots, lines or flashes?

Occipital lobe - visual cortex

What is micturition syncope?

A type of vasovagal syncope - common. Expect presyncopal symptoms: 1. Feeling of lightheadedness 2. Nausea 3. Sweating 4. Narrowing of vision During syncope: May see brief limb jerking Key detail: Urination prior to black out.

What is a complex partial seizure?

Complex partial seizure = focal onset impaired awareness seizure A seizure with loss of awareness but no loss of consciousness. Typically lasting 1-2 minutes. Generally a temporal lobe seizure. ``` Symptoms: Prodromal warning (not describable) Automatism (basic oral; chewing, sucking or complex manual; fiddling etc) Becoming unaware of surroundings Wandering ```

What is status epilepticus?

A life-threatening complication of any seizure: It is >5 minutes of continuous/repetitive seizures without regaining consciousness. Rapid intervention is necessary since serious brain injury can occur ``` Types: - follow the types of seizure that can occur Tonic-clinic (convulsive) Focal aware motor Focal impaired awareness Focal aware (sensory) Absence Impaired awareness cognitive Non-convulsive; hard to diagnose, they may just seem absent ```

What is a psychogenic non-epileptic attack AKA non-epileptic attack disorder?

A seizure caused by mental or emotional processes, not by physical cause (a functional condition). The most common type is dissociative seizures where the subconscious causes the seizures, so they have no control over them. Other types: panic attacks, factious (some conscious control)

What is an absence seizure?

A type of non-motor generalised onset seizure. (AKA petit mal) ``` Features: Abrupt onset Altered awareness Oral and manual automatisms Clonic movements of face (eyelids,head, eyebrows, chin) ```

What is a generalised tonic-clonic seizure?

A type of generalised motor seizure, occurs with loss of consciousness. Comes in two stages: 1. Tonic - increased tone (seconds to minutes) 2. Clonic - sustained rhythmic jerking Can also come in different order (clonic-tonic-clonic or myoclonic-tonic-clonic)

What is a generalised clonic seizure?

A bilateral rhythmic jerking with loss of consciousness.

What is a generalised tonic seizure?

A bilateral increased tone of the limbs lasting seconds to a minute. Most often occurs in sleep, can cause drop attack (sudden fall without loss of consciousness). May have a vibratory component if they last longer, this can be confused with clonic jerking.

What is a myoclonic seizure?

A single or series of brief jerks (unlike clonic which is rhythmic jerks). Can cause a drop attack (fall without loss of consciousness).

What is a myoclonic-atonic seizure?

A myoclonic seizure (brief jerk/jerks) followed by an atonic seizure (loss of tone, body goes floppy).

What is an atypical absence seizure?

Like an absence seizure but with slower onset and slower loss of awareness. Associated symptoms: Gradual loss of muscle tone in head, trunk or limbs

What are some of the most common causes of seizures?

Hypoglycaemia - especially in people with low GCS | Hyponatremia/hypernatremia - especially in the post-operative period due to improper IV fluid use

Is there a provocation in epilepsy?

Some types of epilepsy can have seizures triggered by stimuli (e.g. photosensitive epilepsy).

What are the reversible causes of seizure?

Note: anyone would have a seizure given the right circumstances Alcohol withdrawal Benzodiazepine withdrawal Metabolic disturbance: hypoxia, Hypernatremia, hyponatremia, Hypercalcemia, hypocalcaemia, glucose, Uraemia, liver disease Infection (eg meningitis, encephalitis) Hyperthermia drugs (tricyclics, cocaine)