Brain tumors- Neurosurgery Flashcards
General manifestations of Brain tumors
Manifestations due
to Increased ICP:
-Headache
-Blurring of vision
-Nausea
-Projectile vomiting
-Seizures
Regional manifestation of Frontal lobe tumor (CP)
- Contralateral face, arm or leg weakness
- Expressive dysphasia (dominant hemisphere)
- Personality changes:
1. Antisocial behavior
2. Loss of inhibitions
3. Intellectual impairment
4. Profound dementia especially if the corpus cullosum is involved
Regional manifestation of Parietal lobe tumors (CP)
- Disturbed cortical sensation
a. Tactile localization
b. Two-point discrimination
c. Steroegnosis
d. Sensory inattention - Visual field defect: lower homonymous hemianopia
- In dominant hemisphere: Gerstmann’s syndrome
1. Right/left confusion
2. Finger agnosia
3. Acalculia
4. Agraphia - Non dominant hemisphere: e.g. Sensory or motor hemineglect syndrome.
Regional manifestation of Temporal lobe tumors
- Psychomotor epilepsy
- Receptive dysphasia (dominant hemisphere).
- Visual defect: upper homonymous quadratanopia
Regional manifestation of Occipital lobe tumors:
- visual field defect (homonymous hemianopia)
- visual hallucination
- cortical blindness.
Regional manifestation of Supra sellar tumors as pituitary adenoma and craniopharyngioma
- bitemporal hemianopia
- hormonal dysfunction
- hypothalamic manifestations.
Regional manifestation of Tumors affecting Corpus cullosum
- Interhemispheric disconnection syndrome
1- Left side apraxia
2- Pure word blindness or alexia without agraphia
Regional manifestation of Posterior fossa tumors
- obstructive hydrocephalus due to obstruction of the 4th ventricle
- cerebellar manifestations as:
1- tremors
2- ataxia
3- dysmetria
4- nystagmus.
Regional manifestation of Cerebellopontine angle tumors
as acoustic schwannoma; cerebellar manifestations and cranial nerve dysfunction:
* Trigeminal: facial hypothesia, neuralgia, loss of corneal reflex.
* Facial: facial palsy
* Vestibulocochlear: tinnitus and sensory neural hearing loss
* Lower cranial nerves: difficult swallowing, loss of gag reflex and frequent aspiration
Investigations used in brain tumors
Radiological:
1- MRI brain with GAD (gadolinium):
the golden diagnostic tool as it defines clearly the tumor extension and its relation to the surrounding structures.
2- CT brain with contrast:
superior to the MRI in the delineation of bony structures and/or tumor calcification
3- Angiography: to study the vascularity of the tumor and its relationship with important vascular structures.
4- Plain x-ray:
a- Calcification as in oligodendroglioma, craniopharyngioma.
b-Osteollytic lesions in primary or secondary bone tumors, Chordomas
c- Erosion of the posterior clinoids from local pressure as in cranipharyngioma
d- Ballooning of the sella in large pituitary adenoma.
e- Pineal shift: seen if the gland is calcified
5- SPECT and PET scan:
helps identify high-grade activity within a tumor. Useful to exclude if proposing conservative management or in planning stereotactic biopsy
Laboratory:
1- Routine investigations
2- Hormonal assay: for pituitary adenomas, craniopharyngiomas or any tumor compressing the pituitary stalk.
3- Tumor markers: important with germ cell tumors e.g. α-fetoprotein
4- CSF analysis: lumber puncture is contraindicated if the clinician suspects an intracranial tumor. If CSF is obtained by another source e,g ventricular drainage or during shunt insertion, then cytological examination may reveal tumor cells
ttt of brain tumors
1- Surgical excision
2- Biopsy
3- Conventional Radiotherapy
4- Stereotactic Radiosurgery
5- Proton Beam therapy
6- Chemotherapy
7- Medical treatment;
a) Steroid (edema)
b) Antiepileptics (Epileptic fits)
C)Dopamine agonist (Pituitary adenomas)
D) Dehydrating (ICP)
Subdivisions of Gliomas
a) Astrocytoma: arise from astrocytes and represent the most primary intra-axial brain tumor
b) Oligodendroglioma: arise from oligodendrocytes that normally form the myelin sheath in the white matter.
c) Ependymoma: arise from the ependymal lining of the ventricles
d) Mixed tumors as oligoastrocytoma
Most common locations of meningioma and its ttt
❖ Parasagittal (along the superior sagittal sinus).
❖ Convexity (along the convexity dura)
❖ Falcine (along the falx cerebri).
❖ Tentorial (along the tentorium).
❖ Basal (along the skull base). E.g., olfactory groove, tuberculum sellae, sphenoid wing, clival, cerebellopontine angle).
❖ Intraorbital (optic nerve sheath).
❖ Intraventricular (within the ventricles).
- Surgical treatment should be total excision of the tumour whenever possible with its dural attachment.
- Subtotal excision of the tumor or incomplete excision of its dural attachment will result in increased recurrence rate.
- Radiotherapy is usually reserved for tumors with aggressive histological features.
Common signs and symptoms of Medulloblastoma and site
Site: It usually arises from the roof of the fourth ventricle producing obstructive hydrocephalus.
- Intracranial hypertension manifestations due to hydrocephalus.
- Cerebellar dysfunctions, most manifested as truncal ataxia, dysmetria and nystagmus.
- Leptomeningeal dissemination causing back pain and/or lower limbs
- Neurological deficits.
Ttt of medulloblastoma
- surgical excision of the tumour followed by adjuvant therapy.
- Ventriculo-peritoneal shunt for CSF diversion may be performed prior to tumor excision if significant hydrocephalus exists.
