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Biomedical subjects

T M Bosley

Publications and source records attributed to T M Bosley.

At least 19 recordsLinked to original sources
PubMed2006

Increased relative mitochondrial DNA content in leucocytes of patients with NAION.

AIM: To investigate possible changes in relative mitochondrial DNA (mtDNA) content in patients with non-arteritic anterior ischaemic optic neuropathy (NAION). METHODS: 19 patients with NAION were compared to 32 controls matched for age, sex distribution, and ethnicity. DNA was extracted from leucocytes and competitive multiplex polymerase chain reaction was carried out with two primer pairs (one pair for mtDNA ND1 gene and the other pair for beta actin nuclear gene) in the presence of a fluorescent dye. RESULTS: The mean relative mtDNA content in controls (0.93 (SD 0.11); 95% CI 0.89 to 0.97) was significantly less than in NAION patients (2.40 (1.05); 95% CI 1.90 to 2.91; p < 0.001). Relative mtDNA content was negatively correlated with Snellen visual acuity (Spearman's rho; r = -0.37; p = 0.022). CONCLUSION: Increased relative mtDNA content in NAION patients may imply a response to oxidative stress, possibly in part because of mitochondrial respiratory chain defects. Significantly more non-synonymous mtDNA nucleotide changes, significantly increased relative mtDNA content, and a significant association between relative mtDNA content and visual acuity all imply that mitochondrial abnormalities may be a risk factor for NAION.

Adult↗
PubMed2005

Neurologic features of horizontal gaze palsy and progressive scoliosis with mutations in ROBO3.

OBJECTIVE: To review the neurologic, neuroradiologic, and electrophysiologic features of autosomal recessive horizontal gaze palsy and progressive scoliosis (HGPPS), a syndrome caused by mutation of the ROBO3 gene on chromosome 11 and associated with defective decussation of certain brainstem neuronal systems. METHODS: The authors examined 11 individuals with HGPPS from five genotyped families with HGPPS. Eight individuals had brain MRI, and six had electrophysiologic studies. RESULTS: Horizontal gaze palsy was fully penetrant, present at birth, and total or almost total in all affected individuals. Convergence, ocular alignment, congenital nystagmus, and vertical smooth pursuit defects were variable between individuals. All patients developed progressive scoliosis during early childhood. All appropriately studied patients had hypoplasia of the pons and cerebellar peduncles with both anterior and posterior midline clefts of the pons and medulla and electrophysiologic evidence of ipsilateral corticospinal and dorsal column-medial lemniscus tract innervation. Heterozygotes were unaffected. CONCLUSIONS: The major clinical characteristics of horizontal gaze palsy and progressive scoliosis were congenital horizontal gaze palsy and progressive scoliosis with some variability in both ocular motility and degree of scoliosis. The syndrome also includes a distinctive brainstem malformation and defective crossing of some brainstem neuronal pathways.

Adolescent↗
PubMed2002

Familial horizontal gaze palsy with progressive scoliosis maps to chromosome 11q23-25.

Horizontal gaze palsy with progressive scoliosis (HGPS) is a rare, autosomal recessive disorder characterized by a congenital absence of conjugate horizontal eye movement, with progressive scoliosis developing in childhood or adolescence. The authors identified two unrelated consanguineous families with HGPS. Genomewide homozygosity mapping and linkage analysis mapped the disease locus to a 30-cM interval on chromosome 11q23-25 (combined maximum multipoint lod score Z = 5.46).

Adolescent↗
PubMed2001

Abnormal development of the lesser wing of the sphenoid with microphthalmos and microcephaly.

We report two patients with abnormal development of the lesser wing of the sphenoid bone, globe, optic nerve and cerebral hemisphere without stigmata of neurofibromatosis type 1. The lesser wing of the sphenoid bone was abnormally formed and was not ossified ipsilateral to the dysmorphic eye and underdeveloped cerebral hemisphere. Maldevelopment of the sphenoid wing may interfere with the normal closure of the optic vesicle and normal growth of encephalic structures, possibly by disturbing developmental tissue interactions. These patients may exhibit a type of restricted primary sphenoid dysplasia, while the sphenoid dysplasia of neurofibromatosis type 1 may be secondary to orbital or ocular neurofibromas and other factors associated with that disease.

Child↗
PubMed2001

Homozygous mutations in ARIX(PHOX2A) result in congenital fibrosis of the extraocular muscles type 2.

Isolated strabismus affects 1-5% of the general population. Most forms of strabismus are multifactorial in origin; although there is probably an inherited component, the genetics of these disorders remain unclear. The congenital fibrosis syndromes (CFS) represent a subset of monogenic isolated strabismic disorders that are characterized by restrictive ophthalmoplegia, and include congenital fibrosis of the extraocular muscles (CFEOM) and Duane syndrome (DURS). Neuropathologic studies indicate that these disorders may result from the maldevelopment of the oculomotor (nIII), trochlear (nIV) and abducens (nVI) cranial nerve nuclei. To date, five CFS loci have been mapped (FEOM1, FEOM2, FEOM3, DURS1 and DURS2), but no genes have been identified. Here, we report three mutations in ARIX (also known as PHOX2A) in four CFEOM2 pedigrees. ARIX encodes a homeodomain transcription factor protein previously shown to be required for nIII/nIV development in mouse and zebrafish. Two of the mutations are predicted to disrupt splicing, whereas the third alters an amino acid within the conserved brachyury-like domain. These findings confirm the hypothesis that CFEOM2 results from the abnormal development of nIII/nIV (ref. 7) and emphasize a critical role for ARIX in the development of these midbrain motor nuclei.

Amino Acid Sequence↗
PubMed2000

Canalis basilaris medianus: MRI.

We report the MRI appearances of an developmental anatomical variant of the basiocciput, with neuroimaging findings (CT and MRI). Such variants are commonly asymptomatic, but may be associated with episodes of meningitis.

Child↗
PubMed2000

Ophthalmological and intracranial anomalies in patients with clinical anophthalmos.

PURPOSE: To better describe the clinical and neuroimaging spectrum of abnormalities in clinical anophthalmos. METHODS: We performed a retrospective review of all 17 patients admitted to the King Khaled Eye Specialist Hospital with clinical anophthalmos over a 15 year period who had a complete ophthalmological examination documented and received computed tomographic (CT) imaging of the orbits and brain. RESULTS: Patients with clinical anophthalmos had a high incidence of developmental abnormalities involving both eyes (15/17 patients, 88%), the brain (12/17 patients, 71%) and the body (7/12, 58%). The incidence of central nervous system anomalies reached 100% in patients with bilateral small optic nerves on CT scan. CONCLUSIONS: Patients with clinical anophthalmos share a similar constellation of neurological, somatic and neuroradiological abnormalities as patients with microphthalmos, septo-optic dysplasia and clinical optic nerve hypoplasia. This fact may provide insight into developmental abnormalities of the afferent visual system and brain.

Abnormalities, Multiple↗
PubMed1999

Microvascular cranial nerve palsies in an Arabic population.

OBJECTIVES: The incidence of microvascular ocular cranial nerve palsies may be increasing with the prevalence of diabetes in the developing world. We review this problem for the first time in an Arabic population. MATERIALS AND METHODS: This is a prospective nonrandomized study of all patients with the diagnosis of microvascular cranial mononeuropathy seen in the Neuro-ophthalmology Clinic at the King Khaled Eye Specialist Hospital between September 1997 and April 1998. RESULTS: Forty-seven patients with microvascular palsies of cranial nerves 3, 4, or 6 were seen in this 8-month period. Compared to previous studies, this group had a stronger association with previously diagnosed diabetes mellitus, more males affected, and a longer duration of the cranial nerve palsy before complete resolution. Five patients had an unusual clinical course that included a second microvascular cranial mononeuropathy before the first palsy completely resolved. CONCLUSIONS: Microvascular cranial nerve palsies may occur more frequently in this Arabic population than elsewhere and may have certain unusual features.

Adult↗
PubMed1998

Giant cell arteritis in Saudi Arabia.

PURPOSE: To obtain information about the incidence of giant cell arteritis in Saudi Arabia. METHODS: Retrospective review of all temporal artery biopsies performed at the King Khaled Eye Specialist Hospital from December 1982 to January 1998. RESULTS: Seventy-two temporal artery biopsies were performed over this 15 year period, of which four were positive for giant cell arteritis. CONCLUSIONS: The incidence of GCA in Saudi Arabia is probably less than in the United States and Western Europe.

Aged↗
PubMed1995

Hemifacial spasm and osteitis deformans.

PURPOSE/METHODS: A patient with osteitis deformans (Paget's disease) and hemifacial spasm underwent magnetic resonance tomographic angiography. Bone-modulating bisphosphonates and botulinum injection were administered to treat the hemifacial spasm. RESULTS/CONCLUSIONS: Computed tomography showed marked temporal bone overgrowth. Magnetic resonance tomographic angiography showed no vascular compression of the facial nerve root. The hemifacial spasm failed to resolve with intravenous pamidronate. Subsequent botulinum injection rendered the patient spasm free for 22 weeks. Further research on the use of bisphosphonates in the treatment of pagetoid hemifacial spasm is required.

Aged↗
PubMed1995

Relative pupillary sparing third nerve palsies. To arteriogram or not?

Ten consecutive patients with acute relative pupillary sparing third nerve palsies were enrolled in a prospective study to determine the prevalence of intracranial aneurysm. All patients were imaged with either cerebral angiography or magnetic resonance angiography. None of the patients demonstrated an intracranial aneurysm. The prevalence of aneurysm in patients with relative pupillary sparing third nerve palsies may be low enough to preclude the use of routine angiography in this condition.

Acute Disease↗
PubMed1995

Pain in anterior ischemic optic neuropathy.

PURPOSE: The diagnoses of both anterior ischemic optic neuropathy (AION) and optic neuritis are clinical ones with significant overlap of symptoms and signs. This study investigates the presence and character of pain at the onset of AION, in order to evaluate this symptom as a differentiating diagnostic feature between optic neuritis and AION. METHODS: Forty-one consecutive patients over 45 years of age with a clinical syndrome consistent with AION were questioned about the presence and character of associated pain. RESULTS: Pain was reported by 12% (5 of 41) of the patients with AION. This is contrasted with data compiled on 448 patients in the optic neuritis treatment trial, of whom 92.2% complained of pain. CONCLUSION: While there is overlap in the incidence and character of pain in AION and optic neuritis, its presence/absence remains a useful differentiating feature.

Aged↗
PubMed1994

Combined central retinal vein occlusion and cilioretinal artery occlusion associated with prolonged retinal arterial filling.

We examined four healthy men who developed cilioretinal artery occlusion associated with central retinal vein occlusion. Unlike previously reported patients with this clinical entity, there appeared to be abnormal central retinal artery inflow, as evidenced by prolonged, irregular filling of the branch retinal arteries with intravenous fluorescein angiography. The patients were treated with systemic corticosteroids. All of the patients had initial improvement in vision. However, three of the four patients had recurrent episodes of visual loss. The final visual acuity was 20/40 or better in three of the four patients.

Adult↗