Acoustic Neuroma

D E FI N I T ION

Schwann cell-derived tumours that commonly arise from the vestibular

portion of the eight cranial nerve. More than 90% of cases are unilateral. Bilateral cases

are seen in neurofibromatosis type 2.

AETIOLOGY 

Risk factors include:

. Neurofibromatosis type 2.

. Exposure to loud noise.

. Childhood exposure to low-dose radiation for benign conditions of the head and neck.

EPIDEMIOLOGY

 Incidence is one in 100 000 per year. The median age at diagnosis is

approximately 50 years. Account for8%of all intracranial tumours in adults and 80–90%

of cerebellopontine angle tumours.

HISTORY 

Symptoms of cranial nerve compression by the tumour:

VIII nerve: Hearing loss (95%), tinnitus and unsteadiness while walking.

V nerve: Facial numbness, paraesthesia and pain (17%).

VII nerve: Facial weakness (6%).

With tumour progression (expansion into the cerebellopontine angle):

Compression of the cerebellum resulting in ataxia.

Compression of the lower cranial nerves (IX, X and XI) resulting in dysarthria and dysphagia.

EXAMINATION

 Abnormal cranial nerve examination:

VIII nerve: Hearing loss, the Weber and Rinne tests suggest asymmetric sensorineural hearing

impairment, nystagmus (beating away from tumour).

V nerve: Loss of corneal reflex, facial numbness.

VII nerve: Lower motor neuron facial palsy.

Cerebellar compression: Ipsilateral ataxia and nystagmus.

Look for signs of neurofibromatosis.

INVESTIGATIONS 

Audiometry: Asymmetric sensorineural hearing loss.

Brainstem-evoked response audiometry: Delay in nerve conduction time on the affected side.

MRI with gadolinium contrast: Sshows acoustic neuromas in the region of the internal

auditory canal with variable extension into the cerebellopontine angle.

MANAGEMENT 

Surgery is aimed to prevent further disability and does not restore hearing.

There are three operative approaches: retromastoid suboccipital, translabyrinthine and

middle fossa.

Radiation therapy: Stereotactic radiosurgery (using multiple convergent beams to deliver a

high single dose of radiation) may be considered for neuromas<3 cm and in patients unfit

for surgery. Stereotactic radiotherapy (using focused doses of radiation given over a series

of treatment sessions) and proton beam therapy may also be used. The choice of therapy

depends upon the availability of the appropriate expertise and patient preferences.

COMPLICATIONS 

Compression of brainstem and the fourth ventricle resulting in hydrocephalus,

increased intracranial pressure and death can occur in untreated cases.

PROGNOSIS 

Hearing loss is often permanent. Treatment merely prevents further damage

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PH.Jafar Jassim 1/30/2021 11:22:00 م

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Alzheimer’s disease

D E F I N I T I ON

 Primary chronic progressive neurodegenerative dementia1 characterized by

extracellular deposition of b-amyloid protein2 and intracellular neurofibrillary tangles.

Mild cognitive impairment: Impairment in some cognitive domains but insufficient to qualify

for diagnosis of dementia or to affect quality of life.

AET IOLOGY

 Unknown cause. Majority of cases are idiopathic with rare monogenic cases.

Risk factors include age, prior intellectual level and family history.

Pathophysiology: Characterised by extracellular deposition of amyloid plaques containing

b-42 peptides and intracellular accumulation of neurofibrillary tangles containing hyperphosphorylated

tau protein (microtubule protein). It remains unclear which is the

causative pathology. Neurone count is reduced particularly in hippocampus, mesial

temporal and precuneate cortex.

E P IDEMI OLOGY 

Very common, affecting 5% of those >65 years and accounts for

60–80% of all dementias. Diagnosis before age 60 years is exceptional. The incidence

" exponentially with age.

H ISTORY 

Reliable history is best obtained from relative.

Gradual deterioration of cognitive functions:

. Initially, anterograde amnesia, change of personality, apathy, loss of concentration and

disorientation. May be accompanied with psychiatric manifestations (hallucinations and

delusions).

. Language is typically spared until late.

. In late stages, cognitive impairment in all cognitive domains (memory, language, visuospatial),

myoclonus, seizures, behavioural disturbances, incontinence and loss of

independence.

EXAMI N A T ION 

Mini-Mental State Exam (MMSE) is a useful screening tool (<27 qualifies

for dementia) but premorbid intellectual function needs to be taken into account.

Typically, in amnestic Alzheimer’s, delayed recall is impaired even with prompting.

I N V E S T IGATIONS 

Investigations are aimed at excluding treatable causes of dementia.

Blood: FBC, U&E, LFT, ESR, CRP, TFT (exclude hypothyroidism), folate, ANA, ANCA, vitamin

B12, treponemal serology. Consider HIV serology.

CT/MRI-brain: May show cerebral or hippocampal atrophy. Useful for excluding tumours,

infarction, inflammatory causes, subdural haematoma.

Psychometric testing: Useful for defining domains of impairment. May be helpful for

distinguishing depressive pseudo-dementia.

Electroencephalography: Not diagnostic, but may be useful to exclude non-convulsive status

epilepticus as a cause.

Lumbar puncture: Not usually necessary except if disease is relatively subacute onset or rapid

to exclude other causes (e.g. encephalitis, prion disease). Tau and b-42 peptide levels can

also be measured.

Nuclear imaging: Primarily research tools. 11C-PIB PET can image amyloid distribution in brain

and 99mTc-HMPAO-SPECT shows regional hypoperfusion of affected cerebral regions.

MANAGEMENT

 Best provided by multidisciplinary team composing of psychiatrist, social

worker, neuropsychologist.

1 Dementia is the significant impairment of memory and one or more other domain of cognition (language,

visuospatial skills and praxis) in a setting of clear consciousness and interfering with work, social activities or

relationships.

2 b-amyloid deposition can also occur in the cerebral arteries causing cerebral amyloid angiopathy. This is

typified by lobar haemorrhages and can be detected by MRI-gradient echo sequences.

Treatment of intercurrent illness or exarcebating factors: Avoid sedative drugs, antimuscarinic

agents and alcohol, environmental management.

Adaptations: Medicalert bracelet, memory aids (diaries, labels).

Pharmacological: Anticholinesterase inhibitors (e.g. rivastigminem donepezil, galantamine)

are only licensed for mild to moderate disease and provide only modest benefit.

Social: Manage psychological impact of disease on carer and patient. Initiate social support

systems early before advanced disease requires institutional care. Early discussion of endof-

life care may be helpful.

COMPLLI C A T IONS

 Poor quality of life, loss of independence, devastating effect on

family.

PROGNOSIS 

The average life expectancy from diagnosis is between 3 and 8 years.

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PH.Jafar Jassim 12/24/2020 12:54:00 ص

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Bell’s palsy

D E F I N I T I ON 

Idiopathic lower motor neurone facial (VII) nerve palsy.

AET IOLOGY

 Idiopathic. Sixty percent are preceded by an upper respiratory tract infection,

suggesting a viral or post-viral aetiology.

E P IDEMI OLOGY

 Annual incidence is 15–40 in 100 000. Most cases: 20–50 year.

H ISTORY

 Prodrome of pre-auricular pain in some cases followed by acute (hours/days)

onset unilateral facial weakness and droop. Maximum severity within 1–2 days.

Fifty percent experience facial, neck or ear pain or numbness.

Hypersensitivity to sound (hyperacusis caused by stapedius paralysis).

Loss of taste sense (uncommon).

Tearing or drying of exposed eye.

EXAMI N A T ION 

Lower motor neurone weakness of facial muscles (affects all the ipsilateral

muscles of facial expression and does not spare the muscles of the upper part of the face

as seen in UMN facial nerve palsy).

Bell’s phenomenon: Eyeball rolls up but eye remains open when trying to close the eyes.

Although patient may report unilateral facial numbness, clinical testing of sensation is

normal. The ear should be examined to exclude other causes (e.g. otitis media, herpes

zoster infection).

I N V E S T IGATIONS

 Usually unnecessary except to exclude other causes, e.g. Lyme serology,

herpes zoster serology.

EMG: May show local axonal conduction block in facial canal. Only useful >1 week after

onset.

MANAGEMENT 

Protection of cornea with protective glasses/patches and artificial tears.

High-dose corticosteroids (prednisolone) is beneficial within 72 h (given only if Ramsay

Hunt’s syndrome is excluded). Little evidence for aciclovir.

Surgery: Lateral tarsorrhaphy (suturing the lateral parts of the eyelids together) if imminent or

established corneal damage.

COMPL I C A T IONS 

Corneal ulcers, eye infection. Aberrant reinnervation may occur, e.g.

blinking may cause contraction of the angle of the mouth as a result of simultaneous

innervation of obicularis oculi and ori. Parasympathetic fibres may also aberrantly reinnervate

causing ‘crocodile tears’ when salivating.

P ROGNOS I S

 Most (85–90%) recover function within 2–12 weeks with or without

treatment.

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PH.Jafar Jassim 12/24/2020 12:51:00 ص

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Carotid artery disease

D E FI N I T ION 

Narrowing of the carotid artery by atherosclerosis; a common cause of

stroke.

AE T IOLOGY 

Atheromatous plaque at the common carotid bifurcation or any of the

carotid branches can cause stroke or blindness by distal embolization, thrombosis or low

flow. The carotid artery bifurcation is an area of the vascular tree where atherosclerosis is

common. In combination with systemic risk factors, local haemodynamics, including low

shear stress and " turbulence affecting the outer walls opposite theflowdivider pre-dispose to

atheroma development, luminal narrowing and risk of plaque rupture, thrombosis or

embolism.

E P IDEMIOLOGY 

Common, third leading cause of death in UK and major cause of longterm

disability, "incidence with age, more common in men.

H ISTORY

Often asymptomatic.

Amaurosis fugax: Transient unilateral vision loss—‘like a curtain coming down’ caused by

embolism into the ophthalmic artery (internal carotid artery branch).

Transient ischaemic attacks (TIAs): Focal symptoms lasting <24 h may be a precursor of a

stroke. (see Transient ischaemic attack).

Crescendo TIAs: TIAs that increase in duration, severity or frequency. This is associated with a

critical stenosis of the internal carotid artery, carotid dissection and may require anticoagulation

or carotid endarterectomy.

Stroke: Persistant neurological deficit (dependent on region affected by infarct). (see Stroke).

EXAMINA T I ON 

If asymptomatic, often no abnormality on examination.

A carotid bruit, if present, does not reflect the degree of stenosis.

Signs of TIA or CVA (e.g. dysarthria, dysphasia, weakness in limbs).

INVE S T I G A T IONS Duplex Doppler carotid ultrasound: Non-invasive imaging to assess

degree of stenosis. There are two criteria of assessing degree of stenosis (NASCET or

ECST), and the method of evaluation needs to be noted.

CT, CTA, MRI and MRA: Brain and carotid imaging.

Angiography: Invasive (risk of precipitating stroke 1%), enables very accurate assessment

of stenosis severity.

MANAGEMENT The EXPRESS

 study (Early use of eXisting PREventive Strategies for Stroke,

Lancet 2007) showed that urgent assessment and treatment reduced the 90-day risk of

recurrent stroke by 80%. All patients should be seen in a TIA clinic (urgency determined

by ABCD2 scoring).

Medical treatment: Low-dose aspirin, stopping smoking and treatment of other risk factors,

hypercholesterolaemia, hypertension and diabetes, for:

. asymptomatic stenosis,

. <70% internal carotid artery stenosis (ECST criteria),

. <50% (NASCET criteria), or

Surgical treatment: Carotid endartectomy within 2 weeks of stroke or TIA reduces risk of

further stroke in ECST and NASCET trials, although carries a significant peri-operative risk.

May be considered in:

. symptomatic stenosis of 70–99% (ECST criteria),

. symptomatic stenosis of 50–99% (NASCET criteria) or

. crescendo TIAs not responding to medical treatment.

The role of surgical treatment in asymptomatic disease is controversial.

Angioplasty þ/ stenting: Under evaluation compared to carotid endarterectomy for

symptomatic disease. The SPACE and EVA-3S trials failed to show non-inferiority of

Carotid artery disease (continued

carotid stenting vs. endarterectomy. The ICSS trial showed that carotid endarterectomy is

superior to stenting at 30-day follow-up, longer follow-up results are pending. The CREST

trial is underway but unlikely to overturn existing evidence.

COMPL I C A T IONS

 Complications of disease: Stroke (thromboembolic or watershed).

Complications from surgery: Cardiac ischaemia or infarction (3%), nerve injury (2–7%,

mandibular branch of facial nerve, recurrent laryngeal nerve or hypoglossal nerves),

haematoma, peri-operative stroke (1–5%). The peri-operative mortality rate is 0.5–1.8%.

P ROGNOS I S

 For carotid artery stenosis of >70%, annual stroke rate is 10–20%. If

untreated, asymptomatic stenosis of <50% has an annual stroke risk of 1%.

If surgically corrected: 6–8 fold relative risk reduction of stroke in 1 year.

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PH.Jafar Jassim 12/19/2020 12:08:00 ص

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Carpal tunnel syndrome

DEFINITION

 Carpal tunnel syndrome (CTS) refers to the symptom complex brought on by

compression of the median nerve in the carpal tunnel.

AE T IOLOGY 

Compression of the median nerve within the carpal tunnel (formed by the

flexor retinaculum superiorly and the carpal bones inferiorly). Usually idiopathic (43%) but

may be secondary to:

Tenosynovitis: Overuse, rheumatoid arthritis, other inflammatory rheumatic disease.

Infiltrative diseases of the canal/increased soft tissue: Amyloidosis, myeloma myxoedema,

acromegaly.

Bone involvement in the wrist: Osteoarthritis, fracture, tumour.

Fluid retention states: Pregnancy, nephrotic syndrome.

Other: Obesity, menopause, diabetes, end-stage renal disease

E P IDEMIOLOGY 

Overall prevalence 2.7%. Incidence in adults 0.1% per year. Lifetime

risk 10%.

H ISTORY 

Tingling and pain in the hand and fingers (patients may be woken up at night).

Weakness and clumsiness of hand.

EXAMINA T I ON

 Sensory impairment in median nerve distribution (first 31/2 fingers).

Weakness and wasting of the thenar eminence (abductor pollicis brevis and opponens)

Tinel’s sign: Tapping carpal tunnel triggers symptoms.

Phalen’s test: Maximal flexion of the wrist for 1 min may cause symptoms. Signs of the

underlying cause, e.g. hypothyroidism or acromegaly.

INVE S T I G A T IONS Blood: TFTs, ESR.

Nerve conduction study: Not always necessary. Shows impaired median nerve conduction

across the carpal tunnel in the context of normal conduction elsewhere.

MANAGEMENT 

Mild to moderate CTS: Nocturnal wrist splinting in the neutral position.

If there is inadequate response: a single injection of methylprednisolone into the carpal

tunnel.

Referral to an occupational therapist/carpal bone mobilization.

Moderate to severe CTS refractory to conservative measures: Surgical decompression.

COM P L IC A T I ONS 

Permanent motor and sensory impairment of the hand.

PROGNOSIS 

Good. Majority of cases wax and wane over years. Secondary cases are more

likely to progress further.

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PH.Jafar Jassim 12/18/2020 01:28:00 ص

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Cervical spondylosis

D E F I N I T I ON 

Progressive degenerative process affecting the cervical vertebral bodies and

intervertebral discs, and causing compression of the spinal cord and/or nerve roots.

AE T IOLOGY

 Osteoarthritic degeneration of vertebral bodies produces osteophytes, which

protrude on to the exit foramina and spinal canal, and compress nerve roots (radiculopathy) or

the anterior spinal cord (myelopathy).

E P IDEMIOLOGY 

The mean age at diagnosis is 48 years. Annual incidence: 107 per

100 000 in men and 64 per 100 000 in women.

H ISTORY

 Neck pain or stiffness. Arm pain (stabbing or dull ache).

Paraesthesia, weakness, clumsiness in hands.

Weak and stiff legs, gait disturbance.

Atypical chest pain, breast pain or pain in the face.

EXAMINA T I ON

Arms:

. Atrophy of forearm or hand muscles may be seen.

. Segmental muscle weakness in a nerve root distribution: C5: Shoulder abduction and

elbow flexion weaknesses. C6: Elbow flexion and wrist extension weaknesses. C7: Elbow

extension, wrist extension and finger extension weaknesses. C8: Wrist flexion and finger

flexion weaknesses.

. Hyporeflexia. In C5 and C6 lesions, ‘inverted’ reflexes may be seen as a result of LMN

impairment at the level of compression andUMNimpairment below the level. Hoffmann’s

sign (flexion of the terminal thumb phalanx when rapidly extending the terminal phalanx

of the 3nd or 3rd finger).

. Sensory loss (mainly pain and temperature).

. Pseudoathetosis (writhing finger motions when hands are outstretched, fingers spread

and eyes closed).

Legs (seen in those with cervical cord compressions):

. " Tone, weakness, hyper-reflexia and extensor plantars.

. # Vibration and joint position sense (spinothalamic loss is less common) with a sensory level

(few segments below the level of cord compression).

Lhermitte’s sign: Neck flexion produces crepitus and/or paraesthesia down the spine.

INVE S T IGATIONS

Spinal X-ray (lateral):May detect osteoarthritic change in the cervical spine. Rarely diagnostic in

non-traumatic cervical radiculopathy. Flexion and extension films are important in the setting

of trauma, and are helpful to evaluate for possible subluxation of one vertebral over another.

MRI: Assessment of root and cord compression and to exclude spinal cord tumour, and nerve

root infiltration by tumour or granulomatous tissue. Many elderly people have some

degree of cervical spondylosis and this may not be the cause of the symptoms.

Needle electromyography (EMG): May reveal a myotomal pattern of denervation.

MANAGEMENT

Conservative: Physiotherapy. Intermittent neck immobilization (soft neck collar), pain management

(e.g. NSAIDs) and restriction of high-risk or aggravating activities. Close

neurologic follow-up should assess for deterioration when surgery is deferred.

Acute deterioration is a neurologic emergency. Confirm the diagnosis with MRI. Seek surgical

consultation. IV methylprednisolone within 8 h of acute deterioration.

Surgery (for more severe myelopathy or progressing deficits): Spinal decompression, facetectomy,

laminectomy (only about 50% improve after surgery).

COM P L I CAT I ONS 

Lower cervical roots, particularly C7, are more frequently affected.

Acute spinal cord compression. Bladder and sphincter dysfunction.

PROGNOSIS

 If untreated, there can be a high quality of life impairment. Surgical treatment

may only partially alleviate the impairment.

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PH.Jafar Jassim 12/16/2020 10:54:00 م

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