Chronic phalaris toxicity in eastern grey kangaroos (Macropus giganteus).

CASE REPORT: Seven eastern grey kangaroos (Macropus giganteus) grazing pastures including Phalaris spp. in Victoria showed neurological deficits characterised by ataxia, head tremors and collapse. Gross examination of the brains and spinal cords of affected kangaroos showed a greenish discolouration in several regions of the grey matter. Histologically, intracytoplasmic accumulation of pigment granules was detected in the neurons, most prominently in the thalamus, brainstem and ventral horns of the spinal cord. Pigment granules were positive to stains used for identification of melanin, including Fontana-Masson stain and Schmorl's reaction. CONCLUSION: The combination of clinical signs and obvious neuronal pigmentation is consistent with chronic Phalaris spp. toxicity, a condition well documented in domestic ruminants.

A survey to detect the presence of Mycobacterium avium subspecies paratuberculosis in Kangaroo Island macropods.

The aim of this study was to determine whether Mycobacterium avium subspecies paratuberculosis (M. a. paratuberculosis) infection was present in macropods grazing with infected sheep on Kangaroo Island in 2001-2002, and to assess the likely role of such infection in the epidemiology of ovine paratuberculosis. Ileum and associated lymphatics from 482 macropods were examined using radiometric culture followed by PCR for IS900 and restriction endonuclease analysis (REA) for species identification, and isolates were strain typed using PCR for IS1311 and REA. Ileum and mesenteric lymph nodes from animals with positive tissue cultures or gross lesions suggestive of paratuberculosis were examined histologically. Faeces from a total of 840 animals were cultured in pools of 20, and individual faecal cultures were done from tissue culture positive animals, from those with microscopic lesions, and from selected animals with gross lesions. Eight animals (1.7%) yielded positive tissue cultures, and all isolates were the sheep (S) strain. Two animals that were tissue culture positive also had histopathological evidence of paratuberculosis. Twelve culture negative animals had microscopic lesions consistent with mycobacterial infection, and M. genavense was identified by PCR from a paraffin block from one of these animals. All faecal cultures were negative. These results indicate that a small proportion of macropods can become infected with M. a. paratuberculosis when grazing with infected sheep. However, excretion of large numbers of viable organisms is rare in macropods, and it is unlikely that macropods provide a wildlife reservoir of infection that would seriously compromise control efforts for paratuberculosis in sheep.

Intermittent exotropia increasing with near fixation: a "soft" sign of neurological disease.

AIM: To examine the association of distance-near disparity with neurological disease in children with intermittent exotropia. METHODS: A retrospective analysis was performed of the medical records of all children with intermittent exotropia examined at the Arkansas Children's Hospital between 1989 and 2002. The study group consisted of children with intermittent exotropia who had a near deviation that exceeded the deviation at distance by at least 10 prism dioptres. The control group consisted of children with intermittent exotropia who had a distance deviation greater than or equal to the deviation at near. The main outcome measures were the prevalence of neurological abnormalities in the study and control groups. RESULTS: Among the 29 patients in the study group, 19 (66%) had a history of concurrent neurological abnormalities. Associated neurological conditions included developmental delay (10 patients), attention deficit disorder (four patients), cerebral palsy (four patients), history of intracranial haemorrhage (four patients), periventricular leucomalacia (three patients), seizures (two patients), cortical visual impairment (two patients), hydrocephalus (one patient), history of anoxic brain damage (one patient), history of encephalitis (one patient), and autism (one patient). Among the 37 patients in the control group, seven (19%) had a history of concurrent neurological abnormalities. The difference in the prevalence of neurological disease between the study group and the control group was significant (p = 0.0002). CONCLUSION: Intermittent exotropia increasing with near fixation is associated with neurological disease in children.

Intermittent exotropia increasing with near fixation: a "soft" sign of neurological disease.

AIM: To examine the association of distance-near disparity with neurological disease in children with intermittent exotropia. METHODS: A retrospective analysis was performed of the medical records of all children with intermittent exotropia examined at the Arkansas Children's Hospital between 1989 and 2002. The study group consisted of children with intermittent exotropia who had a near deviation that exceeded the deviation at distance by at least 10 prism dioptres. The control group consisted of children with intermittent exotropia who had a distance deviation greater than or equal to the deviation at near. The main outcome measure was the prevalence of neurological abnormalities in the study and control groups. RESULTS: Among the 29 patients in the study group, 19 (66%) had a history of concurrent neurological abnormalities. Associated neurological conditions included developmental delay (10 patients), attention deficit disorder (four patients), cerebral palsy (four patients), history of intracranial haemorrhage (four patients), periventricular leucomalacia (three patients), seizures (two patients), cortical visual impairment (two patients), hydrocephalus (one patient), history of anoxic brain damage (one patient), history of encephalitis (one patient), and autism (one patient). Among the 37 patients in the control group, seven (19%) had a history of concurrent neurological abnormalities. The difference in the prevalence of neurological disease between the study group and the control group was significant (p=0.0002). CONCLUSION: Intermittent exotropia increasing with near fixation is associated with neurological disease in children.

Strabismus surgery in the treatment of paralytic strabismus.

Strabismus surgery may restore limited binocular function and improve cosmesis in patients with paralytic strabismus. Evaluation of the amount of residual function of the affected extraocular muscles is essential to determine which surgical procedure will yield the best results. Standard muscle resection techniques are effective for patients who have paretic extraocular muscles with residual function. Muscle transposition procedures are indicated for patients with total paralysis of an extraocular muscle. Autogenous and alloplastic materials may be required to fix the eye in primary position in patients with total paralysis of multiple extraocular muscles. This article discusses the recent literature regarding the evaluation and management of patients with paralytic strabismus. Current concepts regarding extraocular muscle transposition and the use of autogenous materials are emphasized.

Magnetic resonance diagnosis of congenital hypopituitarism in children with optic nerve hypoplasia.

PURPOSE: To determine whether structural abnormalities of the neurohypophysis, as detected by magnetic resonance imaging (MRI), can be used to diagnose hypopituitarism in children with optic nerve hypoplasia. METHODS: Retrospective analysis of 67 children with optic nerve hypoplasia who had MRI and pediatric endocrinologic evaluation at Arkansas Children's Hospital from 1989 to 1999. RESULTS: A total of 26 children with optic nerve hypoplasia had pituitary hormone deficiency. MRI disclosed posterior pituitary ectopia in 16 of these cases, absence of the pituitary infundibulum and posterior pituitary bright spot in 7 of these cases, and a normal neurohypophysis in 3 of these cases. All 41 children with optic nerve hypoplasia and normal endocrinologic function had a normal neurohypophysis. CONCLUSION: MRI of the neurohypophysis can predict when congenital hypopituitarism will be associated with optic nerve hypoplasia.

Superior oblique overaction from local anesthesia for cataract surgery.

Traumatic superior oblique dysfunction from cataract surgery appears to be rare, with only 3 reported cases of postoperative Brown syndrome and 1 reported case of postoperative superior oblique weakness. We are not aware of any prior reports of superior oblique overaction occurring after cataract surgery. We describe a patient with acquired superior oblique overaction as a cause of vertical strabismus after cataract surgery. Ocular torsion analysis was essential in localizing the malfunction to the superior oblique muscle. The most likely etiology is myotoxicity from inadvertent intramuscular injection of local anesthetic before cataract surgery.

The orbit.

The orbit contains the globe, extraocular muscles, and their cranial nerve supply. Orbital diseases may damage these structures, resulting in decreased vision and ocular motility deficits. Any process that increases the volume of the orbit may displace the globe and cause proptosis or ocular dystopia. This article focuses on several orbital diseases that present with neuro-ophthalmic signs.

Congenital ocular motor apraxia with autosomal dominant inheritance.

PURPOSE: To document congenital ocular motor apraxia in five first-degree relatives. METHODS: Case series. Five family members with a history of horizontal head thrusting had neuro-ophthalmologic evaluation. Magnetic resonance imaging of the brain was obtained in the proband. RESULTS: Four siblings (one boy and three girls) had congenital ocular motor apraxia. The father had head thrusting as a child and displayed residual signs of the disorder. Magnetic resonance imaging disclosed no central nervous system abnormalities in the father. CONCLUSION: Congenital ocular motor apraxia can be inherited as an autosomal dominant trait.

Carotid-cavernous fistulas.

Carotid-cavernous fistulas often cause ophthalmologic manifestations that may result in loss of vision. Knowledge of these ocular signs is essential for prompt diagnosis and treatment. Appropriate management frequently involves multiple specialists including neuro-ophthalmologists, interventional radiologists, and neurosurgeons. This article reviews current concepts essential to all specialists who treat patients with carotid-cavernous fistulas.

Fourth cranial nerve palsy in pediatric patients with pseudotumor cerebri.

PURPOSE: To describe three children with acute fourth cranial nerve palsy secondary to pseudotumor cerebri. METHODS: We reviewed the medical records of children younger than 18 years who were diagnosed with pseudotumor cerebri between 1977 and 1997. Pseudotumor cerebri was defined by normal neuro-imaging, elevated intracranial pressure measured by lumbar puncture, and normal cerebrospinal fluid composition. RESULTS: Three children with pseudotumor cerebri presented with vertical diplopia and clinical signs of fourth cranial nerve palsy including a hypertropia of the affected eye, which increased with adduction and ipsilateral head tilt. The fourth cranial nerve palsy resolved after reduction of the intracranial pressure in all three children. CONCLUSIONS: Fourth cranial nerve palsy may occur in children with pseudotumor cerebri and may be a nonspecific sign of elevated intracranial pressure.

Optic neuritis in African Americans.

OBJECTIVE: To describe the clinical profile of demyelinating optic neuritis in African Americans. METHODS: The medical records of all patients with a diagnosis of optic neuritis examined at the Neuro-Ophthalmology Unit at the Emory University Eye Center (Emory) and at the Grady Memorial Hospital Eye Clinic (Grady), Atlanta, Ga, between 1989 and 1996 were retrospectively reviewed. PATIENTS: African American and white patients, aged 15 through 55 years, with a single initial episode of acute optic neuritis of unknown or demyelinative origin were included in the study. Study patients included 23 African American patients and 56 white patients examined at Emory as well as 10 African American patients examined at Grady. RESULTS: There were no significant differences among the African American study patients, the white study patients, and patients from the Optic Neuritis Treatment Trial (ONTT) regarding sex (P=.36), age (P=.73), or the presence of disc edema (P=.40), lesions found on magnetic resonance imaging (P=.43), or multiple sclerosis (P=.54) at the onset of an initial episode of optic neuritis. The Emory African American patients presented with more frequent severe visual loss (13 [93%] of 14 patients with a visual acuity < or =20/200) compared with Emory white patients (12 [39%] of 31 patients; P=.002) and with ONTT patients (161 [36%] of 448 patients; P<.001). At follow-up examination of at least 1 year, Emory African American patients had worse vision (9 [39%] of 23 patients <20/40, and 4 [17%] of 23 patients < or =20/200) compared with Emory white patients (5 [8%] of 63 patients <20/40, P=.001; 3 [5%] of 63 patients < or =20/200, P=.08), and with ONTT patients (29 [7%] of 409 patients <20/ 40, P=.0001; 12 [3%] of 409 patients < or =20/200, P=.01). Compared with ONTT patients, the Emory African American patients combined with the Grady African American patients had more frequent severe visual loss (visual acuity < or =20/200) at presentation (18 [90%] of 20 patients vs 161 [36%] of 448 patients; P<.001) and at follow-up examination of at least 1 year (6 [18%] of 33 patients vs 12 [3%] of 409 patients; P=.002). Seven (58%) of 12 African American patients with multiple sclerosis had a "neuromyelitis optica" presentation defined by the presence of neurological deficits limited to the optic nerves and spinal cord. CONCLUSIONS: The African American study patients with a single episode of demyelinating optic neuritis had visual acuities more severely affected at onset and after 1 year of follow-up compared with the white study patients and with patients in the ONTT. In the African American patients, multiple sclerosis occurred most frequently in a "neuromyelitis optica" form.

Pseudotumor cerebri in children.

PURPOSE: Demographic and outcome data in the era of modern neuroimaging are needed to describe pseudotumor cerebri in children. METHODS: We reviewed the medical records of children less than 18 years old who were diagnosed with pseudotumor cerebri between 1977 and 1997. We defined pseudotumor cerebri as (1) increased intracranial pressure, (2) normal or small ventricles, and (3) normal cerebrospinal fluid composition. The condition might be idiopathic or the result of a nontumor etiology. RESULTS: Thirty-seven patients had an initial diagnosis of pseudotumor cerebri. Two patients were subsequently diagnosed with a central nervous system malignancy and were excluded from further analysis. The remaining 35 patients included 10 patients with idiopathic pseudotumor cerebri and 25 patients with disorders reported to be associated with pseudotumor cerebri. The mean age was 10.6 years with a range of 3 to 17 years. Twenty patients (57%) were female and 13 patients (37%) were obese. At presentation 4 patients had a visual acuity less than 20/40 in the best eye and 10 patients had visual field deficits. Seventeen patients (49%) had cranial nerve deficits, all of which resolved with normalization of the intracranial pressure. Follow-up data were obtained on 30 patients. Only one patient had a final visual acuity less than 20/40 in the best eye, whereas six patients had residual visual field deficits. Ten patients (33%) had optic nerve atrophy. CONCLUSIONS: There was no gender predominance, and associated etiologic factors were common in these children with pseudotumor cerebri. Permanent visual loss occurs in some children with pseudotumor cerebri. Quantitative perimetry and optic nerve examination were more sensitive than visual acuity determination in detecting damage to the visual sensory system. In rare instances the patient diagnosed with pseudotumor cerebri will be found after extended follow-up to harbor an intracranial neoplasm.

Painless orbital apex syndrome from mucormycosis.

A 66-year-old woman with a history of non insulin-dependent diabetes mellitus, hypertension, and hypothyroidism presented with a painless orbital apex syndrome without any sign of orbital cellulitis or acute systemic disease. Her blood glucose was mildly elevated, but there was no diabetic ketoacidosis. Neuroimaging revealed only mild sinus disease. Transnasal sphenoidal mucosal biopsy showed an inflammatory mass with cellular atypia on frozen sections, suggesting squamous cell carcinoma. However, review of the permanent sections showed broad, nonseptate hyphae consistent with mucormycosis. The patient was treated with a 3-month course of intravenous amphotericin B and no further surgery. Examination 3 months after presentation revealed complete resolution of her ocular motility deficits and partial resolution of her optic neuropathy. Mucormycosis should be suspected in any case of orbital apex syndrome, especially in the diabetic patient.

Neuro-ophthalmologic manifestations of adenoid cystic carcinoma.

Intracranial adenoid cystic carcinoma is uncommon. We report two unusual cases of intracranial adenoid cystic carcinoma. The first patient presented with a steroid-responsive optic neuropathy from an orbital mass that simulated orbital pseudotumor, and subsequently developed intracranial involvement, presumably by contiguous perineural spread. The second patient presented with proptosis of the left eye, right facial weakness and numbness, and an intracranial mass, presumably from hematogenous metastatic spread.