**Question:** All of the following are known complications of tuberculous meningitis except -

A. Encephalopathy
B. Epilepsy
C. Brain abscess
D. Subarachnoid hemorrhage

**Core Concept:**
Tuberculous meningitis is a severe complication of Mycobacterium tuberculosis infection, predominantly affecting the meninges, brain parenchyma, and sometimes the spinal cord. The disease presents with a wide range of neurological manifestations due to the direct invasion of the central nervous system (CNS) by the bacteria.

**Why the Correct Answer is Right:**
D. Subarachnoid hemorrhage is not a direct complication of tuberculous meningitis. Although cerebral aneurysms can be seen in the context of tuberculosis, subarachnoid hemorrhage is due to rupture of these aneurysms, which is a separate entity unrelated to the direct effects of M. tuberculosis infection on the CNS.

**Why Each Wrong Option is Incorrect:**
A. Encephalopathy is a general term for derangement of brain function caused by various factors, including infections like tuberculosis. Although encephalopathy can occur in tuberculous meningitis, it is not an exclusive complication of this disease.

B. Epilepsy can result from tuberculous meningitis due to cerebral edema, neuronal damage, or inflammation. However, epilepsy is not a specific complication of tuberculous meningitis compared to other meningitis cases.

C. Brain abscess is a localized collection of pus within the brain due to bacteria, parasites, or other pathogens. Although brain abscess can occur in the context of tuberculous meningitis, it is not a unique complication of this disease.

**Clinical Pearl:**
The key to remember is that subarachnoid hemorrhage is a distinct entity unrelated to tuberculous meningitis, while encephalopathy, epilepsy, and brain abscess are complications that can result from tuberculous meningitis but are not specific to this condition compared to other meningitis cases.