Isolated Fourth Nerve Palsy in Tuberculous Meningitis.

Tuberculous meningitis is a type of subacute meningitis and like other intracranial processes can compromise ocular motor nerves, causing palsies. Trochlear nerve is an unusual isolated manifestation in this type of pathology. The authors report a 5-year-old boy presented in their clinic with a trochlear nerve palsy as unique neurological manifestation of tuberculous meningitis. Treatment with complete anti-tuberculous therapy and botulinum A toxin was needed to get the complete resolution of the nerve palsy. In tuberculous meningitis, the presence of high protein levels and higher number of cells in cerebrospinal fluid is associated with cranial nerve involvement. Usually cranial nerve palsies occur in combination. VI cranial nerve alone or a combined disorder of VI and III cranial nerves are the palsies most frequently presented. Much less common is an isolated disorder of IV cranial nerve in the course of meningitis. The length of full treatment with anti-tuberculous therapy in this case was of 1 year. The persistence of palsy 1 month after the beginning of the symptoms indicated the possibility of a botulinum toxin injection with complete resolution of the process without disability, ocular motility has remained normal on follow-up.