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Show Journal of Neuro- Ophthalmology 17( 4): 278- 281, 1997. © 1997 Lippincott- Raven Publishers, Philadelphia Letters to the Editor To the Editor: In their paper entitled " Convergence nystagmus associated with spasmus nutans," Massry et al. ( 1) reported on a 6- month- old infant with spasmus nutans and the unique feature of an associated convergence nystagmus. We report here on a similar case that was recently treated by us in the Neuro- Ophthalmology Unit at Emory University. A 2- year- old boy presented with an 18- month history of head nodding and nystagmus. He was otherwise healthy with no other signs or symptoms of neurologic disease. He was not taking any medications, and there was no family history of nystagmus. The clinical course had been characterized by head nodding and nystagmus, which waxed and waned in severity over 18 months, and by the recent onset of torticollis. Magnetic resonance imaging ( MRI) of the brain was normal at age 6 months. Ophthalmic examination at 2 years of age showed central fixation maintained equally with both eyes. The preferred head position was chin down with a right tilt. The orbits, lids, anterior segment, and pupils were entirely normal. Examination of ocular alignment using Hirsch-berg's method showed a left hypertropia of - 10 prism diopters which was worse on right gaze, and a small right hypertropia on left gaze. He had full ductions and versions with overaction of the inferior obliques bilaterally. There was a rapid, fine horizontal nystagmus in both eyes that appeared to be pendular and disconjugate ( i. e., convergent/ divergent). Funduscopic examination was normal, as was the remainder of the neurologic examination. Repeat MRI with gadolinium was again normal. The findings of a small- amplitude, rapid nystagmus along with head nodding and torticollis in the setting of an otherwise normal examination and MRI scan are, as in the case reported by Massry et al., suggestive of spasmus nutans. The two cases have an interesting similarity in that both demonstrated the unique feature of horizontal nystagmus with the eyes moving in opposite directions. However, in the case reported by Massry et al, the nystagmus was described as convergent in nature and is therefore assumed to be jerk nystagmus with the fast phase directed medially. In our case, the nystagmus was pendular in nature and we therefore characterize it as convergent/ divergent. The additional findings, in our case, of a left hypertropia worse on right gaze and right hypertropia on left gaze are diagnostic of bilateral fourth nerve palsies. The torticollis ( chin down, right head tilt) is likely attributable to weaker superior oblique function on the left. We appreciate the report by Massry et al. of their unusual case and would be most interested in a clarification of the nature of the nystagmus in that case. Was it truly jerk nystagmus with the fast phase in the direction of convergence? Or was it similar to our case in having pendular horizontal nystagmus that was convergent/ divergent? Baker Hubbard, M. D. Kimberly Terry, M. D. Valerie Biousse, M. D. Nancy J. Newman, M. D. Departments of Ophthalmology, Neurology, and Neurosurgery Emory University School of Medicine Atlanta, Georgia, U. S. A. REFERENCE 1. Massry GG, Bloom JN, Cruz OA. Convergence nystagmus associated with spasmus nutans. J Neuroophthalmol 1996; 16: 196- 8. 3- Methylglutaconic Aciduria: A New Metabolic Disorder Associated with Early Onset Optic Atrophy To the Editor: In 1909, Behr ( 1) described a heredofamilial syndrome of optic atrophy beginning in early childhood that was associated with pyramidal signs, ataxia, mental retardation, urinary incontinence, and pes cavus. Behr syndrome ( BS) has since been reported in both sexes and is considered an autosomal- recessive disorder ( 2). Over time, it became evident that the so- called BS was diagnosed in patients who suffered from heterogeneous progressive neurologic disorders. Indeed, McKusick states that BS must be, at best, a " mixed bag" and thus cannot be regarded as a unique syndrome [ McKusick no. 210000 ( 3)]. In 1989, Costeff et al. reported 19 patients of Jewish- Iraqi origin, many of them the product of consanguineous marriage. The uniform clinical picture consisted of early optic atrophy, spastic paraparesis, and involuntary movements ( 4). In 1993, the same investigators reported that their patients excreted in the urine increased amounts of the organic compounds 3- methyl-glutaconic acid and 3- methylglutaric acid ( 5). With the aid of a distinct laboratory marker, they were able to expand their patient population. It soon became evident that children and adults alike have been diagnosed after a prolonged delay, during which multiple sclerosis, cerebral palsy, mitochondrial encephalopathy, and a variety of other conditions have been entertained ( 5). The large number of newly diagnosed patients made possible the characterization of the main features of this new metabolic disorder. This form of 3- methylglutaconic aciduria ( 3- MGA) can present during infancy ( 6). Optic atrophy may be overlooked at 278 LETTERS TO THE EDITOR 279 this early age or it may appear much later ( Staraussberg et al., manuscript in preparation). Spastic paraplegia or paraparesis is uniformly present and is indeed the cardinal clinical sign in infancy. Cognitive functions are usually within the normal range. Brain computed tomography and magnetic resonance imaging, electroencephalography, and evoked potentials are usually normal except for low- amplitude visual evoked potentials with normal latency of P100. The gene frequency of 3- MGA in Iraqi Jews in Israel is 0.01 ( 3), whereas its incidence in other ethnic groups must be extremely low. Al Aqeel et al. ( 7) reported on 10 patients with 3- MGA from Saudi- Arabia. However, these patients had heterogeneous neurologic and clinical symptomatology distinctly different from the Iraqi- Jewish form. When optic atrophy is detected in infancy, childhood, or adolescence, especially in patients of Iraqi- Jewish stock, a search for 3- MGA should be mandatory. Unfortunately, the concentration of 3- MGA in amniotic fluid is not enough to enable prenatal diagnosis. This may be overcome when the search for a mutation in genomic DNA of the affected families will be successfully completed. The nature of the metabolic error causing 3- MGA is yet unknown. Defects in cholesterol synthesis, mitochondrial respiratory chain, leucine degradation, and peroxisomal functions have been suggested but not proven ( 8,9). Anat Kesler, M. D. Department of Neurology Sapir Medical Center, Meir Hospital Sackler School of Medicine, Tel Aviv University Kfar Saba, Israel Natan Gadoth, M. D. Department of Neurology Rabin Medical Center, Beilinson Campus Sackler School of Medicine, Tel Aviv University Petach Tikvah, Israel Rachel Straussberg, M. D. Department of Neurology Schneider Children's Medical Center Sackler School of Medicine, Tel Aviv University Petach Tikvah, Israel REFERENCES 1. Behr C. Die komplizierte, hereditar- familiare Optikusatrophie des Kindesalters. Klin Monatsbl Augenheilkd 1909; 47: 138- 60. 2. Miller NR. Walsh and Hoyt's Clinical Neuro- ophthalmology. Baltimore: Williams & Wilkins; 1982: 321- 25. 3. McKusick VA. Mendelian Inheritance in Man. Baltimore: Johns Hopkins University Press; 1992. 4. Costeff H, Gadoth N, Apter N, Prialnic M, Savir HA. Familial syndrome of infantile optic atrophy, movement disorder and spastic paraplegia. Neurology 1989; 39: 595- 7. 5. Costeff H, Elpeleg O, Apter N, Divery P, Gadoth N. 3- Methylglutanic aciduria in " optic atrophy plus." Ann Neurol 1993; 33: 103^ 1. 6. Elpeleg ON, Costeff H, Joseph A, Shental Y, Weitz R, Gibson KM. 3- methylglutaconic aciduria in Iraqi- Jews " optic atrophy plus." Dev Child Neurol 1994; 36: 167- 72. 7. Al Aqeel A, Rashed M, Ozand PT, et al. 3- Methylglutaconic aciduria: ten new cases with a possible new phenotype. Brain Dev 1994; 16: 23- 32. 8. Narisawa K, Gibson KM, Sweetman L, et al. Deficiency of 3- methylglutaconyl- coenzyme A hydratase in two siblings with 3- methylglutaconic aciduria. J Clin Invest 1986; 77: 148- 52. 9. Gibson KM, Lee CF, Wappner RS. 3- methylglutaconyl coenzyme A hydratase deficiency: a new case. J Inherited Metab Dis 1992; 15: 363- 6. Normal Pressure Pseudotumor Cerebri To the Editor: In their article '' ' Normal Pressure' Pseudotumor Cerebri," Green et al. ( 1) reported a case of an 18- year- old woman with clinical features suggestive of pseudotumor cerebri ( PTC) but without elevated intracranial pressure ( ICP). We would like to report a similar case. A 31- year- old, 5.4- feet tall, 130- pound white woman presented with an 18- month history of tinnitus, transient visual obscurations, and intermittent moderate headache. She was otherwise healthy with no other signs or symptoms of neurologic disease. She was not taking any medication. The clinical course had been characterized by left- sided tinnitus, brief transient visual obscurations in the left eye when bending, and moderate headache described as " fullness of the head" over 18 months. Ophthalmologic examination, repeated over 15 months, had shown bilateral disk edema that was not present on a previous funduscopic examination 3 years before. Computed tomographic scan and magnetic resonance imaging ( MRI) of the brain had been normal. A lumbar puncture had shown normal cerebrospinal fluid ( CSF), but the opening pressure had not been measured. After lumbar puncture, she experienced a severe postural headache related to CSF hypotension. Tinnitus and visual symptoms had resolved for about 3 months but had then recurred. Ophthalmologic examination by us showed normal visual acuity in both eyes. Pupils were normal. Slit- lamp examination and motility were unremarkable. Funduscopic examination showed bilateral chronic disk elevation worse on the left, with venous dilation. Goldmann visual fields showed bilateral enlarged blind spot and inferior nasal depression in the left eye. Neurologic examination was unremarkable. MRI of the brain and orbits with gadolinium was repeated and was again normal except for the presence of a partial empty sella turcica. A lumbar puncture showed an opening pressure of 180 mm H20 and normal CSF. Immediately after lumbar puncture, the patient reported resolution of ' ' fullness of the head," tinnitus, and transient visual obscurations. However, the day after, she complained of postural headache with nausea that spontaneously resolved within 20 days. J Neuro- Ophthalmol, Vol. 17. No. 4, 1997 |