Case contribution: Dr. Radhiana Binti Hassan
Clinical:
- A 14 years old boy with no known medical illness
- Presented with bowel and urinary incontinence for one month
- Associated with gait instability and lower back pain.
- On examination, GCS is full, power of LL 4/5. No other neurological deficit.
CT scan findings:
- Plain and contrast-enhanced CT scan performed
- Bilateral and symmetrical enlarged thalami, which are hypodense and show no enhancement post contrast.
- No calcification within the lesion
- Acute hydrocephalus also seen
MRI findings:
- Mass involving both thalami (arrows and star)
- Hypointense on T1 and hyperintense on T2 and FLAIR images
- No enhancement post contrast
- Extension of mass to midbrain
- Effacement of quadrigerminal and ambient cisterns bilaterally
- Ventriculomegaly also seen with transependymal seepage of CSF
- VP shunt in-situ
Progress of patient:
- Right endoscopic examination and right ventriculoperitoneal shunt insertion
- Left Keen’s burr hole and IGS guided biopsy for bithalamic lesion
- Biopsy: low grade glioma with astrocytic differentiation
Diagnosis: Bilateral thalamic glioma
Discussion:
- Bilateral thalamic tumours are extremely rare sub-types of thalamic tumours with poor outcome regardless of treatment modality
- They account for 1-1.5% of all brain tumours and approximately ¼ of them occur in children less than 15 years.
- Clinical presentation include gait unsteadiness, sensory abnormalities, motor deficit, dysmetria, torticollis, nystagmus, personality changes, emotional lability, loss of memory, apathy and cognitive impairment.
- Classic morphological features are diffuse symmetrical enlargement of the thalamic nuclei and the absence of bridging tumour between the two. It typically involve the dorsomedial and intralaminar nuclei of thalami and often spare the adjoining third ventricle, temporal lobes, midbrain and pineal gland until late stages of the disease
