Search PubMed⌕ Search

Biomedical subjects

M Tariq Bhatti

Publications and source records attributed to M Tariq Bhatti.

At least 19 recordsLinked to original sources
PubMed2006

Superior divisional third cranial nerve paresis: clinical and anatomical observations of 2 unique cases.

BACKGROUND: Within the midbrain, the third nerve nucleus is composed of a complex of subnuclei. The fascicular portion of the nerve courses through the red nucleus and exists in the midbrain just medial to the cerebral peduncle. The cisternal portion of the nerve is a single structure that divides into a superior branch and an inferior branch in the region of the cavernous sinus and superior orbital fissure. OBJECTIVE: To describe 2 patients with superior divisional third cranial nerve paresis resulting from a lesion involving the cisternal portion of the nerve prior to its anatomical bifurcation. PATIENTS: Case 1 was a 77-year-old man with a superior divisional third nerve palsy as the presenting manifestation of a posterior communicating artery aneurysm. Case 2 was a 41-year-old woman who developed a superior divisional third nerve palsy following anterior temporal lobectomy for epilepsy. RESULTS: In both cases, the presumed location of the lesion was the cisternal portion of the third cranial nerve. CONCLUSIONS: Although the anatomical division of the third cranial nerve occurs in the region of the anterior cavernous sinus or superior orbital fissure, there is a topographical arrangement of the motor fibers within the cisternal portion of the nerve. The clinical evaluation of a patient with a third cranial nerve paresis requires an understanding of the regional neuroanatomy and topographical organization of the nerve.

Adult↗
PubMed2006

Retinitis pigmentosa, pigmentary retinopathies, and neurologic diseases.

Retinitis pigmentosa (RP) refers to a group of inherited retinal diseases with phenotypic and genetic heterogeneity. The pathophysiologic basis of the progressive visual loss in patients with RP is not completely understood but is felt to be due to a primary retinal photoreceptor cell degenerative process mainly affecting the rods of the peripheral retina. In most cases RP is seen in isolation (nonsyndromic), but in some other cases it may be a part of a genetic, metabolic, or neurologic syndrome or disorder. Nyctalopia, or night blindness, is the most common symptom of RP. The classic fundus appearance of RP includes retinal pigment epithelial cell changes resulting in retinal hypo- or hyperpigmentation ("salt-and-pepper"), retinal granularity, and bone spicule formation. The retinal vessels are often narrowed or attenuated and there is a waxy pallor appearance of the optic nerve head. Electroretinography will demonstrate rod and cone photoreceptor cell dysfunction and is a helpful test in the diagnosis and monitoring of patients with RP. A detailed history with pedigree analysis, a complete ocular examination, and the appropriate paraclinical testing should be performed in patients complaining of visual difficulties at night or in dim light. This review discusses the clinical manifestations of RP as well as describing the various systemic diseases, with a special emphasis on neurologic diseases, associated with a pigmentary retinopathy.

Humans↗
PubMed2006

Progression of visual field defects in leber hereditary optic neuropathy: experience of the LHON treatment trial.

PURPOSE: To describe the visual fields of patients with Leber hereditary optic neuropathy (LHON), a maternally inherited disorder characterized by bilateral, often sequential vision loss, before and during progressive visual deterioration. DESIGN: Prospective longitudinal follow-up of serial visual fields in patients enrolled onto an open-label, nonrandomized pilot study of topical brimonidine purite as prophylactic treatment after first eye involvement in LHON. METHODS: Nine molecularly confirmed primary mutation patients with LHON with monocular vision loss for less than six months and normal visual function in the other eye were followed prospectively for up to two years. Visual fields were performed on automated perimetry at baseline and on many follow-up visits. RESULTS: Despite normal visual acuity at baseline in all patients, seven patients had some minimal changes in the central visual field of the second eye. All patients had subsequent deterioration of visual acuity, mean deviation, and foveal sensitivity in their second eye. The earliest pattern of abnormality was typically a cecocentral defect enlarging to become a central defect, often with a superior or inferior predilection. The visual field defects in the two eyes of any given patient were remarkably similar. CONCLUSIONS: LHON may be a bilateral condition at onset more frequently than appreciated. Automated static perimetry of the "normal" eye may reveal subclinical findings that typically worsen rapidly over weeks to months to similar central scotomatous damage. Quantitative automated static perimetry is helpful in elucidating the natural history of LHON and in understanding the underlying pathology and pathophysiology of this disease.

Administration, Topical↗
PubMed2006

Brainstem stereotactic biopsy sampling in children.

OBJECT: Although it is widely accepted that biopsy sampling is not indicated for the diagnosis and empiric treatment of diffuse pontine glioma, it is common to encounter patients with brainstem lesions that cannot be diagnosed on the basis of imaging studies alone. In cases not amenable to resection, a tissue diagnosis may still be necessary to make appropriate treatment recommendations. The authors retrospectively reviewed their institutional experience with stereotactic biopsy procedures in pediatric patients during a 4-year period. METHODS: A three-dimensional graphics workstation was used for trajectory planning to obtain biopsy samples of brainstem lesions in 10 patients. One patient experienced mild diplopia postoperatively. No other morbidity was noted; no patient died as a result of the procedure. The biopsy procedure yielded a pathological diagnosis in all cases. A later resection in one patient resulted in a change in diagnosis. Overall, the pathological findings were varied, and in some cases the tissue diagnosis altered the treatment recommendations. CONCLUSIONS: The findings in this small series suggest that brainstem stereotactic biopsy sampling in children is a safe procedure with a high diagnostic yield. In patients in whom radiographic findings are not consistent with diffuse pontine glioma and resection is not appropriate, stereotactic biopsy sampling should be considered.

Adolescent↗
PubMed2005

Does altered fractionation influence the risk of radiation-induced optic neuropathy?

PURPOSE: To analyze the parameters that influence the risk of radiation-induced optic neuropathy (RION) after radiotherapy for head-and-neck tumors. METHODS AND MATERIALS: Between 1964 and 2000, 273 patients with tumors of the nasopharynx, paranasal sinuses, nasal cavity, and hard palate adenoid cystic carcinomas were treated with curative intent and had radiation fields that included the optic nerves and/or chiasm. Patients were followed for at least 1 year after radiotherapy. RESULTS: Radiation-induced optic neuropathy developed in 32 eyes of 24 patients (9%). The 5-year rates of freedom from RION according to the total dose and once- vs. twice-daily fractionation were as follows: < or =63 Gy once daily, 95%; < or =63 Gy twice daily, 98%; >63 Gy once daily, 78%; and >63 Gy twice daily, 91%. Multivariate analysis revealed that the total dose affected the risk of RION (p = 0.0047), with patient age (p = 0.0909), once-daily vs. twice-daily fractionation (p = 0.0684), and overall treatment time (p = 0.0972) were marginally significant. The use of adjuvant chemotherapy did not significantly influence the likelihood of developing RION. CONCLUSION: The likelihood of developing RION is primarily influenced by the total dose. Hyperfractionation may reduce the risk of experiencing this complication.

Adrenal Cortex Hormones↗
PubMed2005

Prophylaxis for second eye involvement in leber hereditary optic neuropathy: an open-labeled, nonrandomized multicenter trial of topical brimonidine purite.

PURPOSE: To test a topical agent with purported antiapoptotic properties as prophylactic treatment after first eye involvement in Leber hereditary optic neuropathy (LHON), a maternally-inherited disorder characterized by bilateral, often sequential, visual loss. DESIGN: Open labeled, nonrandomized prospective pilot study. METHODS: Nine primary mutation molecularly confirmed LHON patients with one eye vision loss for less than 6 months and normal visual function in the fellow eye were treated with brimonidine purite 0.15% (Alphagan P) 4 times daily in the unaffected eye for up to 2 years. Visual acuity was the primary efficacy outcome. Secondary measures included changes on automated perimetry and quantification of the relative afferent pupillary defect. RESULTS: There were 8 men and 1 woman enrolled, aged 13 to 54 years (mean 32 years), eight with the 11778 mitochondrial DNA (mtDNA) mutation, and one with the 3460 mutation. Despite normal visual acuity at baseline in all patients, 7 patients had some minimal changes in the central visual field of the study eye. All patients had deterioration of vision in their second eye. In 1 of the 2 patients who had treatment initiated within 16 days after first eye involvement, good visual acuity was maintained in the study eye at 15 month followup, despite a mildly abnormal study eye baseline visual field. CONCLUSIONS: LHON may be a bilateral condition at onset more frequently than appreciated, with asymmetric severity at presentation. Topical brimonidine purite in this dosage was unsuccessful in preventing second eye involvement in recently monocularly-symptomatic LHON.

Administration, Topical↗
PubMed2005

Acute inflammatory demyelinating optic neuritis: current concepts in diagnosis and management.

BACKGROUND: Optic neuritis (ON), defined as an inflammatory demyelinating optic neuropathy, is a frequent cause of visual loss owing to optic nerve dysfunction in young or middle-aged patients. ON can be seen in isolation or in association with multiple sclerosis (MS). Highlighting the importance of this association is the fact that approximately 20% of patients with MS will present with ON. METHODS: Review was conducted of the literature and pertinent clinical trials. CONCLUSION: Although the vision prognosis of patients with ON is excellent, with or without the use of corticosteroids, a minority of patients will suffer from significantly poor vision. ON may be the heralding manifestation of MS; the risk stratification for the future development of MS in patients presenting with ON can be determined by the number of white matter lesions on the baseline cerebral magnetic resonance imaging study. To date, 2 randomized, placebo-controlled studies have found that patients with a clinically isolated demyelinating syndrome, such as ON, at risk for MS, may benefit from the early institution of a disease-modifying drug.

Acute Disease↗
PubMed2005

Neuro-ophthalmic considerations in trigeminal neuralgia and its surgical treatment.

PURPOSE OF REVIEW: In this review, we will briefly discuss the clinical manifestations and etiology of trigeminal neuralgia, outline the neuro-ophthalmic features of trigeminal neuralgia, and detail the neuro-ophthalmic side effects and complications of the surgical treatment of trigeminal neuralgia. RECENT FINDINGS: There is a variety of surgical treatment modalities available for patients with trigeminal neuralgia intolerable or resistant to medical therapy. Significant ocular and visual morbidity can result from the surgical treatment of trigeminal neuralgia. SUMMARY: Percutaneous or open surgical procedures for trigeminal neuralgia can result in corneal anesthesia, neurotrophic keratitis, exposure keratitis, herpetic keratitis, ocular motor cranial neuropathies, and optic neuropathy. Ophthalmologists should be aware of these potential problems because they may need to evaluate and provide care to patients with ocular or visual complaints following surgery for trigeminal neuralgia.

Humans↗
PubMed2005

Visual loss due to central serous chorioretinopathy during corticosteroid treatment for giant cell arteritis.

Giant cell arteritis (GCA) can be a devastating disease resulting in blindness if not promptly diagnosed and treated. The only proven treatment for GCA is systemic corticosteroids; however, there are many side-effects associated with this therapy including ocular side-effects such as ocular hypertension, cataract formation and central serous chorioretinopathy. To raise physician awareness, a patient with biopsy-proven GCA is reported who lost vision during corticosteroid therapy because of central serous chorioretinopathy.

Blindness↗
PubMed2004

Neurologic impairment 10 years after optic neuritis.

BACKGROUND: Participants enrolled in the Optic Neuritis Treatment Trial have been observed for more than a decade to assess the relationship between optic neuritis and the development of clinically definite multiple sclerosis. OBJECTIVE: To assess neurologic disability 10 to 12 years after an initial episode of optic neuritis. DESIGN: Longitudinal follow-up of a clinical trial. SETTING: Fourteen Optic Neuritis Treatment Trial clinical centers performed standardized neurologic examinations, including an assessment of neurologic disability. PARTICIPANTS: One hundred twenty-seven patients who had developed clinically definite multiple sclerosis. MAIN OUTCOME MEASURES: Functional Systems Scale and Expanded Disability Status Scale. RESULTS: The disability of most patients was mild, with 65% of patients having an Expanded Disability Status Scale score lower than 3.0. The degree of disability appeared to be unrelated to whether the baseline magnetic resonance imaging scan was lesion-free or showed lesions (P =.51). Among patients with baseline lesions, the degree of disability was unrelated to the number of lesions that were present on the scan (P =.14). Two patients died owing to severe multiple sclerosis, one of whom had no lesions revealed on the baseline scan. CONCLUSION: Most patients who develop clinically definite multiple sclerosis following an initial episode of optic neuritis will have a relatively benign course for at least 10 years.

Adult↗
PubMed2004

SANDO: another presentation of mitochondrial disease.

PURPOSE: To describe a unique mitochondrial syndrome that may present with the combination of ocular manifestations, sensory symptoms, and speech dysfunction. DESIGN: Case report. METHODS: Case report and review of the literature. RESULTS: A 43-year-old man presented with a Sensory Ataxic Neuropathy, Dysarthria, and Ophthalmoparesis (SANDO). Nerve conduction studies showed a sensory ganglionopathy. Skeletal muscle biopsy revealed ragged red fibers, and polymerase chain reaction analysis of the tissue demonstrated multiple mitochondrial DNA deletions. CONCLUSION: Mitochondrial disease should be considered in cases of external ophthalmoplegia, especially if a sensory ganglionopathy and dysarthria are present.

Adult↗
PubMed2004

Visual function more than 10 years after optic neuritis: experience of the optic neuritis treatment trial.

PURPOSE: To assess visual function more than 10 years after an episode of optic neuritis in patients enrolled in the Optic Neuritis Treatment Trial. DESIGN: Longitudinal follow-up of a randomized clinical trial. METHODS: Vision testing included measures of visual acuity, contrast sensitivity, and visual field. Quality of life was assessed with the National Eye Institute Visual Function Questionnaire. RESULTS: Examinations were completed on 319 patients. In most patients, visual function test results in the eyes that experienced optic neuritis at study entry ("affected eyes") were normal or only slightly abnormal after 9.9 to 13.7 years. Visual acuity in the affected eyes was >or=20/20 in 74%, 20/25 to 20/40 in 18%, <20/40 to 20/200 in 5%, and <20/200 in 3%. On average, visual function was worse in patients with multiple sclerosis (MS) than in those without MS. Recurrent optic neuritis in either eye occurred in 35% of patients. Such attacks were more frequent in patients with MS (P <.001). The National Eye Institute Visual Function Questionnaire scores were lower when visual acuity was abnormal and when MS was present. CONCLUSIONS: Most patients retained good to excellent vision more than 10 years after an attack of optic neuritis. Recurrences were more frequent in patients with MS.

Adolescent↗
PubMed2004

Delayed exacerbation of third nerve palsy due to aneurysmal regrowth after endovascular coil embolization.

A 72-year-old woman with a painful left third cranial nerve palsy due to a basilar artery aneurysm situated between the superior cerebellar and posterior cerebral arteries was treated with Guglielmi detachable coils (GDCs). Despite a good initial angiographic result with a small residual neck and improvement in the ocular motility and pain, the patient experienced worsening of the third cranial nerve palsy 15 months later. Cerebral angiography confirmed coil compaction with aneurysmal regrowth. A second endovascular coil embolization resulted in complete obliteration of the aneurysm. The patient experienced complete resolution of the pain and partial resolution of the third cranial nerve palsy. In some patients, a small residual aneurysm neck after endovascular embolization therapy with GDCs can result in delayed aneurysmal regrowth due to coil compaction. Clinical manifestations may herald this dangerous regrowth.

Aged↗
PubMed2004

The effect of body inclination during prone positioning on intraocular pressure in awake volunteers: a comparison of two operating tables.

Visual loss is a rare, but catastrophic, complication of surgery in the prone position. The prone position increases intraocular pressure (IOP), which may lead to visual loss by decreasing perfusion of the anterior optic nerve. We tested whether the reverse Trendelenburg position ameliorates the increase in IOP caused by prone positioning. Furthermore, we compared two prone positioning set ups. The IOP of 10 healthy awake volunteers was measured in the prone position at 3 different degrees of inclination (horizontal, 10 degrees reverse Trendelenburg, and 10 degrees Trendelenburg) and in the sitting and supine positions in a randomized crossover study comparing the Jackson table and the Wilson frame. In a given eye, all prone IOP values (median [25th-75th percentile] exceeded those of the sitting (15.0 mm Hg [12.8-16.3 mm Hg]) and supine (16.8mm Hg [14.0-18.3 mm Hg]) positions. IOPs in the reverse Trendelenburg, horizontal, and Trendelenburg positions were 20.3 mm Hg (16.3-22.5 mm Hg), 22.5 mm Hg (19.8-25.3 mm Hg), and 23.8 mm Hg (21.5-26.3 mm Hg), respectively (P < 0.001 versus reverse Trendelenburg; dagger P < 0.001 versus horizontal). The reverse Trendelenburg position ameliorated the increase in IOP caused by the prone position. Furthermore, the reverse Trendelenburg position decreased the number of grossly abnormal IOP values (>23 mm Hg) by 50% and 75% compared with the prone horizontal and Trendelenburg positions, respectively. The prone positioning setups did not differ in their effect on IOP. The increase in IOP caused by prone positioning was ameliorated by the reverse Trendelenburg position and was aggravated by the Trendelenburg position. The short time period between changes in position and changes in IOP suggests an important role for ocular venous pressures in determining IOP. Therefore, IOP can be beneficially manipulated by operating table inclination in the prone position.

Adult↗
PubMed2003

High- and low-risk profiles for the development of multiple sclerosis within 10 years after optic neuritis: experience of the optic neuritis treatment trial.

OBJECTIVE: To identify factors associated with a high and low risk of developing multiple sclerosis after an initial episode of optic neuritis. METHODS: Three hundred eighty-eight patients who experienced acute optic neuritis between July 1, 1988, and June 30, 1991, were followed up prospectively for the development of multiple sclerosis. Consenting patients were reassessed after 10 to 13 years. RESULTS: The 10-year risk of multiple sclerosis was 38% (95% confidence interval, 33%-43%). Patients (160) who had 1 or more typical lesions on the baseline magnetic resonance imaging (MRI) scan of the brain had a 56% risk; those with no lesions (191) had a 22% risk (P<.001, log rank test). Among the patients who had no lesions on MRI, male gender and optic disc swelling were associated with a lower risk of multiple sclerosis, as was the presence of the following atypical features for optic neuritis: no light perception vision; absence of pain; and ophthalmoscopic findings of severe optic disc edema, peripapillary hemorrhages, or retinal exudates. CONCLUSIONS: The 10-year risk of multiple sclerosis following an initial episode of acute optic neuritis is significantly higher if there is a single brain MRI lesion; higher numbers of lesions do not appreciably increase that risk. However, even when brain lesions are seen on MRI, more than 40% of the patients will not develop clinical multiple sclerosis after 10 years. In the absence of MRI lesions, certain demographic and clinical features seem to predict a very low likelihood of developing multiple sclerosis. This natural history information is a critical input for estimating a patient's 10-year multiple sclerosis risk and for weighing the benefit of initiating prophylactic treatment at the time of optic neuritis or other initial demyelinating events in the central nervous system.

Acute Disease↗