Neuro - Neoplastic Neurological Conditions

Question 1

Types of Brain Tumours

Secondary Metastases
Gliomas 
Meningiomas 
Pituitary Tumours
Acoustic Neuroma

Answer 1

1. ) Secondary Metastases - common cancers are:
   - lung, breast, renal cell carcinoma, melanoma
2. ) Gliomas - tumours of the glial cells in the brain or spinal cord, there are three types to remember:
   - astrocytoma: glioblastoma multiforme (GBM) is a high-grade astrocytoma and is most common form
   - oligodendroglioma, ependymoma
   - gliomas are graded from 1-4, grade 1 is the most benign and are possibly curable with surgery
3. ) Meningiomas - tumours growing from the cells of the meninges in the brain and spinal cord
   - usually benign, however, but the mass effect can lead to raised ICP and neurological symptoms
4. ) Pituitary Tumours - often benign, but can lead to:
   - bitemporal hemianopia: presses on optic chiasm
   - hormone deficiencies: due to hypopituitarism
   - hormone excess: acromegaly, Cushing’s disease, hyperprolactinaemia, thyrotoxicosis

5.) Acoustic Neuroma - see ENT notes

Question 2

Neurofibromatosis (NF)

Pathophysiology
Diagnostic Criteria for Neurofibromatosis Type 1
Complications of Neurofibromatosis

Answer 2

1. ) Pathophysiology - AD genetic condition causing the development of benign neuromas throughout the nervous system –> neuro and structural problems
   - 2 types, type 1 is more common than type 2
   - NF1 gene is found on chromosome 17, coding for neurofibromin (TSG)
   - NF2 gene is found on chromosome 22, coding for merlin (TSG), particularly important in Schwann cells
2. ) Diagnostic Criteria for Neurofibromatosis Type 1
   - requires 2+ of the 7 features (CRABBING):
   - Café-au-lait spots: >6, >5mm (kids) OR >15mm (adults)
   - Relative with NF1
   - Axillary or inguinal freckles
   - BBony dysplasia: e.g. bowing of a long bone or sphenoid wing dysplasia
   - Iris hamartomas (Lisch nodules): yellow-brown spots on the iris (>2 or more)
   - Neurofibromas: 2+ or 1 plexiform neurofibroma
   - Glioma of the optic nerve
3. ) Complications of Neurofibromatosis - mainly NF1
   - migraines, epilepsy, scoliosis of the spine
   - learning and behavioural problems (e.g. ADHD)
   - vision loss: secondary to optic nerve gliomas
   - renal artery stenosis causing hypertension
   - cancer: brain tumours, SC tumours, malignant peripheral nerve sheath tumours, GI stromal tumours, leukaemia, ↑risk of other types of cancers e.g. breast
   - NF2 is most associated with acoustic neuromas

Question 3

Tuberous Sclerosis

Pathophysiology
Clinical Features
Management

Answer 3

1. ) Pathophysiology - a genetic condition that causes features in multiple systems
   - development of hamartomas (benign neoplastic growths of the tissue that they originated from)
   - cause problems based on the location of the lesion:
   - skin, brain, lungs, heart, kidneys, eyes
   - due to mutation in TSC1 gene on chromosome 9 (codes for hamartin) OR TSC2 gene on 16 (tuberin)
   - hamartin and tuberin control cell size and growth so abnormalities –> abnormal cell size and growth
2. ) Clinical Features - classical presentation
   - child presenting with epilepsy with skin features:
   - ash leaf spots, shagreen patches, angiofibroma, subungual fibromata, cafe-au-lait spots, poliosis
   - other features: learning disability and developmental delay, rhabdomyomas in the heart, gliomas, PCKD, retinal hamartomas, lymphangioleiomyomatosis (abnormal growth in SMCs, often affecting the lungs)
3. ) Management - no treatment for the gene defect
   - supportive with monitoring and treating complications such as epilepsy