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Show ORIGINAL CONTRIBUTION Pontine Tuberculoma Presenting With Horizontal Gaze Palsy Rohit Saxena, MD, Vimla Menon, MS, Ankur Sinha, MD, Pradeep Sharma, MD, Dhivya Ashok Kumar, MBBS, and Harinder Sethi, MD Abstract: A 38- year- old immunocompetent man presented with a horizontal supranuclear gaze palsy as the only neurologic manifestation of a pontine tuberculoma. Although a biopsy of the brain lesion was not performed, it was attributed to tuberculosis because of chest x- ray evidence. The patient was given empirical anti- tuberculous therapy. After one month, the gaze palsy had fully recovered and repeat MRI showed a decrease in the size of the lesion. This is the first reported case of supranuclear gaze palsy without diplopia as a manifestation of a tuberculous brain stem lesion. (/ Neuro- Ophthalmol 2006; 26: 276- 278) n developing countries, tuberculomas may account for up to 40% of space- occupying intracranial masses ( 1). However, isolated brain stem tuberculomas are rare lesions and account for only 5% of all intracranial tuberculomas in endemic areas ( 2). These intracranial masses commonly present as oculomotor and other cranial nerve palsies ( 3- 6), the one- and- a- half syndrome ( 7), unilateral saccadic paralysis ( 8), and other focal neurologic signs ( 3- 6) of brain stem involvement. We describe a case of isolated horizontal gaze palsy due to presumed pontine tuberculoma in an immunocompetent patient. This report documents a rare entity in which gaze palsy was the only manifestation. CASE REPORT A 38- year- old man presented to the Neuro- ophthalmology Service of our center with a 4- week history Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. Address correspondence to Dr. Rohit Saxena, MD, Assistant Professor, Strabismus and Neuro- Ophthalmology Service, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Science, Ansari Nagar, New Delhi- 110029, India; E- mail: rohitsaxena80@ yahoo. com of inability to turn his eyes to the right. There were no other symptoms. Best- corrected visual acuity was 20/ 20 in both eyes. Pupillary reactions and fundi of both the eyes were unremarkable. Ocular motility examination revealed a right gaze palsy with no associated ocular misalignment or nystagmus ( Fig. la- e). There was total absence of rightward saccades and pursuit movements; however, rightward Doll's eye movements and convergence were preserved. The rest of the examination was normal. A hemogram showed an elevated erythrocyte sedimentation rate of 56 mm/ h and a white blood count of 18,400 cells/ mm3 with 55% lymphocytes. The Mantoux test was positive. A T2 brain MRI revealed a well-marginated, nodular, high signal lesion in the right paramedian pons ( Fig. 2a). The lesion measured approximately 15 X 12.9 mm in size with perifocal hyperintense edema arborizing rostrally into the midbrain and caudally into the medulla including the right brachium pontis. The post-contrast Tl brain images showed ring enhancement ( Fig. 2b). A chest x- ray revealed bilateral apical parenchymal infiltrates and consolidation along with bilateral hilar lymphadenopathy ( Fig. 3). Ultrasound of the abdomen was normal. On the basis of these findings, a presumptive diagnosis of tuberculosis was made, and anti- tuberculous therapy was started with a combination of rifampicin 10 mg/ kg per day, isoniazid 5 mg/ kg per day, ethambutol 18 mg/ kg per day, and pyrazinamide 25 mg/ kg per day. After 1 month, right-ward gaze had recovered fully ( Fig. lf- h). A follow- up T2 MRI after 1 month of treatment ( Fig. 2c- d) showed some reduction in the size of lesion. After 3 months of therapy, the patient's condition remained stable. DISCUSSION There have been only 2 case reports in the English literature of an isolated ocular motility abnormality as the only presenting feature of brain stem tuberculoma ( 7,9). In the first report ( 7), the patient presented with diplopia and abnormal eye movements and had a supranuclear gaze palsy together with reduced abduction of the 276 J Neuro- Ophthalmol, Vol. 26, No. 4, 2006 Pontine Tuberculoma J Neuro- Ophthalmol, Vol. 26, No. 4, 2006 FIG. 1. At presentation, there is absent volitional right gaze ( a- c). Passive head turning ( the Doll's eye maneuver) elicits improved right gaze ( d- e). One month after institution of anti- tuberculous therapy, the patient demonstrates full volitional horizontal gaze ( f- h). left eye, which was responsible for diplopia. A postcontrast brain CT scan revealed multiple small areas of signal attenuation in the cerebrum and brain stem. The patient subsequently developed fever, seizures, and abnormal gait and eventually died despite anti- tuberculous therapy. Autopsy revealed multiple caseating granulomas in the liver, kidneys, adrenal glands, right ovary, lungs, and brain indicative of disseminated tuberculosis. . , . . - . . . : l • . , . . jsaEfigpr BMMB w/ f « . jfl ^ ^ - 7 ^ ^^^ S^^^^ B JI FIG. 2. At presentation, T2 axial MRI shows a circumscribed high signal lesion in the right paramedian pons with perilesional edema ( a). Post-contrast T1 axial MRI shows ring enhancement ( b). After 1 month of anti- tuberculous therapy, T2 sagittal ( c) and axial ( d) MRI shows a decrease in the size of the lesion. 277 J Neuro- Ophthalmol, Vol. 26, No. 4, 2006 Saxena et al FIG. 3. At presentation, the chest x- ray shows bilateral apical parenchymal infiltrates and consolidation ( solid arrows) and bilateral hilar lymphadenopathy ( dotted arrows). In the second report ( 9), a 12- year- old girl developed a left gaze palsy associated with reduced adduction of the left eye, resulting in horizontal diplopia on right gaze consistent with an isolated one- and- a- half syndrome. Brain MRI revealed a lesion in the pons and midbrain with an intermediately enhancing signal rim surrounding the lesion. The chest x- ray was normal. A presumptive diagnosis of pontine tuberculoma was made, and anti- tuberculous therapy was continued for 18 months. Repeat brain MRI after 6 months of treatment revealed complete resolution of the lesion, and the patient made a complete clinical recovery. Intracranial tuberculomas occur most commonly in the cerebral and the cerebellar hemispheres, which have relatively profuse blood supplies. Our patient is remarkable in that, despite the apparent size of the tuberculoma on imaging, the only neurologic manifestation was an ipsi-lateral gaze palsy. What is different from the two previous single case reports is that our patient did not have diplopia because the eyes were aligned. The lack of diplopia delayed his presentation to a physician. Acknowledgments The authors thank Dr. Prashant Sarin for assistance with the manuscript. REFERENCES 1. Gupta RK, Jena A, Singh AK, et al. Role of magnetic resonance ( MR) in the diagnosis and management of intracranial tuberculomas. Clin Radiol 1990; 41: 120- 7. 2. Rajshekhar V, Chandy Ml Tuberculomas presenting as isolated intrinsic brain stem masses. Br JNeurosurg 1997; 11: 127- 33. 3. Talamas O, Del Brutto OH, Garcia Ramos G. Brainstem tuberculoma: an analysis of 11 pateints. Arch Neurol 1989; 46: 529- 35. 4. Diaz- Calderon E, Gimeno- Alava A, Diaz A, et al. Tuberculoma of the pons. J Neurol Neurosurg Psychiatry 1981; 44: 266. 5. Sugimori H, Saku Y, Ibayashi S, et al. Solitary pontine tuberculoma. Intern Med 2002; 41: 738^ 12. 6. Venger BH, Dion FM, Rouah E, et al. MR imaging of pontine tuberculoma. AJNR Am J Neuroradiol 1987; 8: 1149- 50. 7. Monteiro ML, Coppeto JR. Cryptic disseminated tuberculosis presenting as gaze palsy. J Clin Neuroophthalmol 1985; 5: 27- 9. 8. Masson C, Prier S, Masson M, et al. Unilateral paralysis of saccades caused by pontine tuberculoma ( in French). Rev Neurol ( Paris) 1989; 145: 652- 5. 9. Menon Y Gogoi M, Saxena R, et al. Isolated " one and a half syndrome" with brainstem tuberculoma. Indian J Pediatr 2004; 71: 469- 71. 278 © 2006 Lippincott Williams & Wilkins |
