Intracerebral Space Occupying Lesions

Intracerebral Space Occupying Lesions

1. Causes

   • Tumour (primary (astrocytoma, glioblastoma multiforme, oligodendroglioma, ependymoma, primary CNS lymphoma, cerebellar haemangioblastoma, meningioma) or secondary (30% - ie breast, lung, melanoma), aneurysm, abscess (25% multiple), chronic subdural haematoma, granuloma, cyst

2. Differential diagnoses

   • Stroke, head injury, vasculitis eg SLE, syphilis, PAN, giant cell arteritis, MS, encephalitis, post-ictal, metabolic, 3rd ventricle colloid cysts, benign intracranial hypertension

3. Investigations

   • CT,MRI. Consider biopsy. Avoid LP (risk of coning)

4. Treatment

   • Benign mass: removal if possible, but may be inaccessible
   • Malignant mass: Excision if possible then consider chemo-radiotherapy. If inaccessible just chemo-radiotherapy. If inaccessible but causing hydrocephalus try ventriculo-peritneal shunt. Give prophylaxis for epilepsy, analgesia ie codeine for headache and give dexamethasone for cerebral oedema and mannitol if acutely raised ICP. Plan palliative treatment.

5. Prognosis

   • Poor but improving for gliomas and benign masses

6. Examples

   • 3rd ventricle colloid cysts
     • Congenital cysts. Present in adulthood with amnesia, headache, obtundation (blunted consciousness), incontinence, dim vision, bilat paraesthesiae, weak legs, drop attacks. Investigations: CT scan/MRI. Treatment: excision or VP shunt
   • Benign intracranial hypertension (pseudotumour cerebri)
     • Present with symptoms of mass (headache, raised ICP, papilloedema) but none found. Typically obese women with blurred vision +/- diplopia, VIth nerve palsy, enlarged blind spot if papilloedema present. Consciousness and cognition are preserved. Cause: Often unknown or secondary to venous sinus thrombosis or drugs ie tetracycline, nitrofurantoin, isoretinoin. Treatment: weight loss, acetazolamide, loop diuretics, prednisalone (may reverse papilloedema). Consider optic nerve sheath fenestration or lumbar-peritoneal shunt if drugs fail and visual loss worsens. Prognosis: often self-limiting, permanent visual loss in 10%

7. Localising signs

   • Temporal lobe: HAPPY-CLAPPY DJ. Hemianopia, Automatisms, Psychosis, Precognition, Yells and falls to floor (type of seizure), (or) Complex-partial seizures, Language disorders, Amnesia, Panic or rage, Pains ie abdo, You do not believe pts bizarre story, Déjà vu, Jamais vu.
   • Frontal lobe: Hemiparesis, motor seizures, personality change, grasp reflex, Broca’s dysphasia, concrete thinking, orbitofrontal syndrome (reduced empathy, inhibition, social skills), utilization behaviour (whatever is provided is used)
   • Parietal lobe: hemisensory loss ie reduced 2 point discrimination
   • Occipital lobe: contralateral visual field defects, hallucinations
   • Cerebellum: DASHING: Dysdiadochokinesis, Ataxia (if trunchal ataxia worse on eye closure then more likely dorsal column pathology), Slurred speech, Hypotonia, Intention tremor, Nystagmus, Gait abnormality
   • Cerebellopontine angle: (ie acoustic neuroma) ipsilateral deafness, nystagmus, reduced corneal reflex, facial weakness (rare), ipsilateral cerebellar signs, papilloedema, VI nerve palsy
   • Corpus callosum: (rare site for lesions) intellectual deterioration, loss of communication between lobes (eg left hand unable to carry out verbal commands)
   • Midbrain: (ie pineal tumours/midbrain infarction) failure of up/down gaze, light/near dissociated pupil responses, nystagmus