Presentation
Patient presented with sudden onset of right upper limb weakness and deviation of angle of mouth. No history of any comorbidites.
Patient Data
Lytic permative bone destruction of the clivus extending to bilateral occipital condyles. Subtle hypodense foci are noted in the left half of pons.
Bones at the craniovertebral junction appear grossly unremarkable.
Altered marrow signal intensity is noted in the clivus and bilateral occipital condyles. These appear hyperintense on T1 and T2 weighted images. Subtle diffusion restriction is noted in the involved areas. There is post contrast enhancement noted in the involved regions with formation of a peripherally enhancing collection in the clivus. Enhancement is noted extending to the atlanto-occipital joint.
Few peripherally enhancing lesions are noted in the pons, which are hyperintense on T2W images. Mild surrounding edema with restricted diffusion is noted. MR spectroscopy from these lesions shows lipid-lactate peak at 0.9 and 1.3ppm. Features are highly suggestive of tuberculomas.
Few centrilobular nodules are noted in the apicoposterior segment of left upper lobe and the apical segment of left lower lobe. Typical matted, necrotic lymph nodes are noted in the mediastinum and in the neck on the right side.
Features are highly suggestive of active infective etiology, such as tuberculosis.
Also noted are few calcific foci in the liver.
CSF study suggestive of raised adenosine deaminase levels and raised CSF proteins.
CSF microscopy suggestive of lymphocytic picture (~20 lymphocytes/hpf).
Overall features suggestive of infective etiology such as tuberculosis.
Case Discussion
Tuberculosis primarily affects the lung. Hematogenous spread of bacilli to the bones usually occurs to the vertebrae followed by long bones 1. Skull base and clival tuberculosis are rare making up about 0.01% of cases of all tuberculosis 2. This rarity maybe because of paucity of lymphatics in the calvarial bone 3.
Diagnosis is also challenging in these areas due to insidious onset of presentation, low bacterial loads in these sites and unapproachable locations for sample collection 2.
Complications of skull base osteomyelitis include thrombosis of dural sinus, jugular foramen syndrome, meningitis, brain abscess, or cervical epidural abscess 4.
Tuberculosis of the clivus region generally runs an indolent course and following appropriate treatment, these patients do well. A high index of suspicion is however needed to make the diagnosis of tuberculosis of the clivus region 5.