Idiopathic congenital nystagmus is characterized by involuntary, periodic, predominantly horizontal oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 singleton cases of idiopathic congenital nystagmus (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina, suggesting a specific role in the control of eye movement and gaze stability.
The findings suggest that nystagmus is more common in the general population than previously thought. This may be of significance in resource allocation and health care planning.
Idiopathic infantile nystagmus (IIN) consists of involuntary oscillations of the eyes. The familial form is most commonly X-linked. We recently found mutations in a novel gene FRMD7 (Xq26.2), which provided an opportunity to investigate a genetically defined and homogeneous group of patients with nystagmus. We compared clinical features and eye movement recordings of 90 subjects with mutation in the gene (FRMD7 group) to 48 subjects without mutations but with clinical IIN (non-FRMD7 group). Fifty-eight female obligate carriers of the mutation were also investigated. The median visual acuity (VA) was 0.2 logMAR (Snellen equivalent 6/9) in both groups and most patients had good stereopsis. The prevalence of strabismus was also similar (FRMD7: 7.8%, non-FRMD7: 10%). The presence of anomalous head posture (AHP) was significantly higher in the non-FRMD7 group (P < 0.0001). The amplitude of nystagmus was more strongly dependent on the direction of gaze in the FRMD7 group being lower at primary position (P < 0.0001), compared to non-FRMD7 group (P = 0.83). Pendular nystagmus waveforms were also more frequent in the FRMD7 group (P = 0.003). Fifty-three percent of the obligate female carriers of an FRMD7 mutation were clinically affected. The VA's in affected females were slightly better compared to affected males (P = 0.014). Subnormal optokinetic responses were found in a subgroup of obligate unaffected carriers, which may be interpreted as a sub-clinical manifestation. FRMD7 is a major cause of X-linked IIN. Most clinical and eye movement characteristics were similar in the FRMD7 group and non-FRMD7 group with most patients having good VA and stereopsis and low incidence of strabismus. Fewer patients in the FRMD7 group had AHPs, their amplitude of nystagmus being lower in primary position. Our findings are helpful in the clinical identification of IIN and genetic counselling of nystagmus patients.
Hydatid cysts commonly affect the liver and the lung. However, they rarely involve bones with vertebral column. We hereby report a case of a female patient with cystic echinococcosis of the hip bone and ilium. She presented with a long history of frequent recurrences highlighting the dismal prognosis at this rare site. Resection of the hydatid cyst from the sacroiliac region was done with allograft and autograft (rib graft) with lumbosacroiliac fixation. Follow-up of the patient at 6 months showed no detectable abnormality on radiology and the patient was doing well.
Background:
Isolated cryptococcal osteomyelitis of the spine is extremely uncommon; there have been only seven cases identified in literature. The majority were originally misdiagnosed as tuberculosis. Here, we present a patient with cryptococcal osteomyelitis of the thoracic spine with associated fungal retinal deposits.
Case Description:
A 45-year-old, type II diabetic female presented with a 5-month history of severe back pain. Her magnetic resonance imaging (MRI) revealed osteomyelitis involving the T4 vertebral body with epidural and prevertebral extension; notably, the intervertebral disc spaces were not involved. Although the fine-needle aspiration cytologic examination was inconclusive, the patient was empirically placed on antitubercular drug therapy. One month later, she became fully paraplegic. The MRI now demonstrated osteolytic lesions involving the T4 vertebral body with cord compression. She underwent biopsy of the T4 vertebral body and a transfacet T4 decompression with T2-T6 pedicle screw fixation. Culture and histopathological examinations both documented a cryptococcal infection, and she was placed on appropriate antifungal therapy. Notably, 3 weeks after surgery, she developed a sudden loss of vision loss due to retinal fungal endophthalmitis. She recovered vision in one eye after the administration of intravitreal voriconazole but lost vision in the other eye despite a vitrectomy. Over the next 8 months, she gradually recovered with motor function of 4/5 in both lower extremities without evidence of recurrent disease.
Conclusion:
Cryptococcal infection should be among the differential diagnostic considerations for patients with vertebral osteomyelitis. Notably, diagnostic delay can lead to devastating neurological deficits and involvement of other organ systems.
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