Coma

Comatose patients are unresponsive to all external stimuli, noxious or otherwise. Neuro-ophthalmic techniques are paramount in the neurologic assessment of comatose patients, especially with regard to brain stem localization and diagnosis. Examination of the pupils, fundi, and corneal reflexes are all helpful; however, the ocular motility examination is especially important because the pathways governing ocular motility traverse the entire brain stem, so pathology in this region often produces recognizable eye movement abnormalities. Conversely, if the eye movements are all normal, it is likely that the entire brain stem is normal. This article details the pupillary, eye movement, and funduscopic abnormalities in coma.

Isolated trochlear nerve palsy in patients with multiple sclerosis

The authors describe five patients with trochlear nerve palsy and MS to characterize this rare association. In two patients, trochlear nerve palsy was the initial clinical manifestation of MS. In the other three patients, this sign occurred after previous neurologic events. MRI did not identify a lesion of the fourth nerve nucleus or fascicle. Ophthalmoplegia resolved within 2 months in four of the five patients. A reason this association is rare is that the fascicular course of the trochlear nerve is exposed to little myelin.

Idiopathic intracranial hypertension: relation of age and obesity in children

The relation between obesity and age in children with idiopathic intracranial hypertension (pseudotumor cerebri) has remained uncertain. The authors reviewed the records of 45 consecutive children with newly diagnosed idiopathic intracranial hypertension seen at two medical centers. Forty-three percent of patients aged 3 to 11 years were obese, whereas 81% of those in the 12- to 14-year age group and 91% of those in the 15- to 17-year age group met criteria for obesity (p = 0.01). Younger children with idiopathic intracranial hypertension are less likely to be obese than are older children or adults.

Neuro-ophthalmologic manifestations of Maffucci's syndrome and Ollier's disease

Patients with Ollier's disease (multiple skeletal enchondromas) and Maffucci's syndrome (multiple enchondromas associated with subcutaneous hemangiomas) may develop skull base chondrosarcomas or low-grade astrocytomas as a delayed consequence of these disorders. We report three patients with Ollier's disease and Maffucci's syndrome who had diplopia as the initial manifestation of intracranial tumors. Since patients with Maffucci's syndrome and Ollier's disease are at risk for the delayed development of brain and systemic neoplasms, neuroophthalmologists must be aware of the need for long-term surveillance in patients affected by these conditions.

Magnetic resonance imaging of acquired Brown syndrome in a patient with psoriasis

PURPOSE

To report the occurrence of acquired Brown syndrome and associated magnetic resonance imaging findings in a patient with psoriasis.

METHODS

A 42-year-old woman with a history of psoriasis developed pain, double vision, and limited elevation of her left eye in adduction. An orbital magnetic resonance image with gadolinium enhancement was obtained.

RESULTS

Orbital magnetic resonance image disclosed abnormal enhancement of the left trochlea/tendon complex. The patient's symptoms resolved with corticosteroid therapy.

CONCLUSIONS

Acquired Brown syndrome may be associated with psoriasis. The inflammation of the trochlea/tendon complex that can cause acquired Brown syndrome can be demonstrated on magnetic resonance image.

Sixth nerve palsies in children

The causes of sixth nerve palsies in 75 children, all of whom had undergone modern neuroimaging, were reviewed. Neoplasms or their neurosurgical removal was the most common cause (n = 34 [45%]); elevated intracranial pressure (nontumor) (15%), traumatic (12%), congenital (11%), inflammatory (7%), miscellaneous (5%), and idiopathic (5%) causes represented other categories but were less commonly present. Isolated sixth nerve palsies were relatively uncommon (9%). On the basis of the relatively high risk of neoplasm, the authors suggest neuroimaging early in the clinical course of children with sixth nerve palsies, even if the palsy is isolated.

Variability in visual cortex activation during prolonged functional magnetic resonance imaging

This study was conducted to test whether cortical activation varies across successive epoques during functional magnetic resonance imaging (fMRI) studies. Ten normal adult volunteers were studied with a 1.5-T MR scanner. Pseudocoronal study planes were chosen perpendicular to the tentorium cerebelli, at two thirds the distance from the posterior edge of the splenium of the corpus callosum to the transverse sinuses. Functional images were acquired with a T2*-weighted spoiled gradient echo sequence. The visual cortex was stimulated by goggles flashing at 8 Hz. Each study consisted of 82 sequential scans, lasting 15 seconds each for a total of 20.5 minutes. Two scans without stimulation were alternated with two scans of visual stimulation. Scans 3 through 83 were divided into five sequences of 16 scans. For each sequence, the number of pixels within a predefined rectangular region of interest that showed increased activity during stimulation were counted. Least squares regression models of straight lines were fit to the data. The initial level of visual cortex activation in the region of interest, as measured by the y-intercept, varied substantially from subject to subject (range: 4-68, p < 0.001). There was sufficient evidence of systematic change with time to reject the hypothesis of constant activation with the same stimulus over time (p=0.02). The observed visual cortex activation with single-plane fMRI varied both with time over successive epoques and among subjects. Possible factors responsible for the variation may include head movement, eyelid position, attention, and physiologic fatigue. These factors must be accounted for in experimental design and in data analysis and interpretation.

Möbius syndrome with oculomotor nerve paralysis without abducens paralysis

Möbius syndrome is typified by bilateral facial nerve palsies, usually with abducens palsies. We examined an infant with Möbius syndrome who had bifacial weakness and third nerve palsies, but intact abduction of both eyes. Lower cranial nerve involvement, leading to respiratory, swallowing, and cardiac difficulties, was also present. Pathologic examination of the brainstem showed absent or hypoplastic third, seventh, tenth, and twelfth nerve nuclei. The fourth, fifth, sixth, and eighth nerve nuclei were intact. In Möbius syndrome with ocular motor palsies, rarely the sixth nerve may be spared.

Acute visual loss and other disorders of the eyes

This article outlines neuro-ophthalmic findings and diseases which may present in an emergency setting. The abnormal optic disc, visual loss, double-vision and disorders of gaze, skew deviation, and the neuro-ophthalmology of vascular lesions, intracerebral hemorrhage, increased intracranial pressure, neuromuscular emergencies, metabolic disturbances, and trauma are all reviewed.

Biomechanical topography of human articular cartilage in the first metatarsophalangeal joint

The objective of this study was to provide a map of cartilage biomechanical properties, thickness, and histomorphometric characteristics in the human, cadaveric first metatarsophangeal joint, to determine if normal articular cartilage was predisposed topographically to biomechanical mismatches in articulating surfaces. Cartilage intrinsic material properties and thickness were obtained from seven pairs of human, freshly frozen, cadaveric, metatarsophalangeal joints using an automated creep indentation apparatus under conditions of biphasic creep. Eight sites were tested: four on the metatarsal head, two on the proximal phalanx base, and one on each sesamoid bone to obtain the aggregate modulus, Poisson's ratio, permeability, shear modulus, and thickness. Cartilage in the lateral phalanx site of the left metatarsal head had the largest aggregate modulus (1.34 MPa), whereas the softest tissue was found in the right medial sesamoid (0.63 MPa). The medial phalanx region of the right joint was the most permeable (4.56 x 10(-15) meter4/Newton-second), whereas the medial sesamoid articulation of the metatarsal head of the left joint was the least permeable (1.26 x 10(-15) meter4/Newton-second). Material properties and thickness are indicative of the tissue's functional environment. The lack of mismatches in cartilage biomechanical properties of the articulating surfaces found in this study may be supportive of clinical observations that early degenerative changes, in the absence of traumatic events, do not occur at the selected test sites in the human first metatarsophalangeal joint.

Pseudopapilledema and congenital disc anomalies in growth hormone deficiency

Optic nerve hypoplasia is a congenital disc anomaly associated with growth hormone deficiency (GHD). Pseudotumor cerebri is an adverse event associated with growth hormone treatment (hGH) and manifested by increased intracranial pressure and papilledema. Pseudopapilledema is a generic ophthalmologic term encompassing several conditions, including congenital disc anomalies. It is benign and can be distinguished from papilledema by physical examination. The objective of this report is to document that congenital disc abnormalities, which can be confused with papilledema, occur in children with GHD. Three patients with GHD had fundoscopic examinations suggestive of papilledema and possibly pseudotumor cerebri. The abnormal optic nerves were characteristic of pseudo-papilledema, and appear to be a variant of optic nerve hypoplasia. The finding of optic disc abnormality during hGH may reflect pseudo-papilledema and not pseudotumor cerebri. Of equal importance, the reported patients indicate that the finding of pseudopapilledema in short children should suggest the possibility of GHD.

Visual impairment associated with mutism after posterior fossa surgery in children

OBJECTIVE

To report four children with visual impairment associated with mutism after posterior fossa surgery. Mutism after posterior fossa surgery is a well-described phenomena, but to our knowledge, visual impairment has not been reported in association with it.

METHODS

Record review of four children (age range, 3-7 yr) who underwent posterior fossa surgery (via suboccipital craniotomies) for removal of a medulloblastoma (three patients) or ependymoma (one patient). Each presented with headache, ataxia, or nausea and vomiting, but none had preoperative visual complaints other than diplopia. Postoperatively, all patients were mute, and because of apparent visual loss, neuro-ophthalmic consultation was requested. Postoperative scans and examinations were also reviewed.

RESULTS

Each child was awake but appeared withdrawn without verbal output. No child blinked to threat or fixed or followed. In each case, pupillary reactivity was normal, and funduscopic examinations revealed only papilledema. One child reached for money. Within weeks or months postoperatively, the mutism spontaneously resolved, and visual behavior in general improved, roughly in parallel. During the follow-up period, papilledema resolved and the disc color was normal in each case. Magnetic resonance images obtained postoperatively revealed nothing remarkable, except surgical defects, without lesions in the retrogeniculate pathway.

CONCLUSION

Impaired visual behavior, mimicking cortical visual loss, may be associated with mutism after posterior fossa surgery in children. The prognosis for recovery is excellent and parallels the return of normal speech. The mechanism is unclear.

Posey and Spiller and progressive supranuclear palsy: an incorrect attribution

In 1904 and 1905, respectively, William Campbell Posey and William Spiller both described the case of a patient with progressive ophthalmoparesis and imbalance that has come to be regarded as the earliest report of progressive supranuclear palsy. No autopsy was thought to have been performed on this patient. In this report, we review the clinical history provided by Posey and Spiller. We also report on the subsequent autopsy of their patient, which was performed by Spiller in 1906. The chief finding was a tumor involving the right cerebral peduncle and periaqueductal area. The autopsy findings prove conclusively that the patient described by Spiller and Posey had a midbrain neoplasm and not progressive supranuclear palsy.

Pseudotumor cerebri and its medical treatment

Pseudotumor cerebri is an idiopathic disorder characterized by papilledema and elevated intracranial pressure without a mass lesion. Most patients are female and young and are either overweight or have a history of recent weight gain. Other disease states, such as systemic lupus erythematosus, and drugs, such as tetracycline, have also been associated with the development of pseudotumor cerebri. The mechanism is unclear, but is likely related to decreased cerebrospinal fluid (CSF) resorption. Almost all patients have headache, but the greatest morbidity of the disorder is visual loss related to optic disc swelling. Common radiographic findings in pseudotumor cerebri include an empty sella, dilation of the optic nerve sheaths and elevation of the optic disc. The CSF, aside from elevated opening pressure, is normal without evidence of infection or inflammation. Treatment of patients with no or mild to moderate visual loss is primarily medical, with acetazolamide as the first-line agent. Acetazolamide decreases CSF production. Furosemide and corticosteroids are secondary choices. Optic nerve surgery is reserved for patients with severe visual loss or progression in visual deficits despite medical management.

Neuro-ophthalmologic aspects of aneurysms

The visual pathways and the ocular motor cranial nerves are frequently injured by expanding cerebral aneurysms. Neuro-ophthalmologic signs and symptoms may be the only indications of an aneurysm prior to rupture. Acute or chronic visual loss may herald an aneurysm prior to rupture. Acute or chronic visual loss may herald an aneurysm in the carotidophthalmic, supra clinoid carotid, internal carotid bifurcation, or anterior communicating artery distributions. Diplopia and retro-orbital pain may be warning signs that precede the discovery of a posterior communicating, basilar, or cavernous sinus aneurysm.

Giant cell arteritis with unusual flow-related neuro-ophthalmologic manifestations

We report two patients with giant cell arteritis and unusual neuro-ophthalmic findings. One patient developed a horizontal one and a half syndrome associated with upright posture. The responsible lesion was dorsal pontine infarction. The other patient had bright light-induced amaurosis fugax in the absence of extracranial carotid occlusive disease. Both patients continued to have symptoms despite the use of high-dose intravenous corticosteroids. The manifestations of both patients occurred early in the course of giant cell arteritis and were flow related.

Neurofibromatosis type 1: brain stem tumours

We describe the clinical and imaging findings of brain stem tumours in patients with neurofibromatosis type 1 (NF1). The NF1 patients imaged between January 1984 and January 1996 were reviewed and 25 patients were identified with a brain stem tumour. Clinical, radiographical and pathological results were obtained by review of records and images. Brain stem tumour identification occurred much later than the clinical diagnosis of NF1. Medullary enlargement was most frequent (68%), followed by pontine (52%) and midbrain enlargement (44%). Patients were further subdivided into those with diffuse (12 patients) and those with focal (13 patients) tumours. Treatment for hydrocephalus was required in 67% of the first group and only 15% of the second group. Surgery was performed in four patients and revealed fibrillary astrocytomas, one of which progressed to an anaplastic astrocytoma. In 40% of patients both brain stem and optic pathway tumours were present. The biological behaviour of brain stem tumours in NF1 is unknown. Diffuse tumours in the patients with NF1 appear to have a much more favourable prognosis than patients with similar tumours without neurofibromatosis type 1.

Comitant esodeviation resulting from neurologic insult in children

PURPOSE

Our purpose was to establish whether comitance was a common or uncommon finding in children with esodeviation associated with a neurologic insult.

METHODS

A retrospective chart review was performed of children with acquired esodeviation associated with an identifiable neurologic insult.

RESULTS

Examinations of 30 children seen over a 2-year period were analyzed. Twenty-two (73%) had brain tumors. Twelve (40%) had comitant esodeviation, and the other 18 (60%) had incomitant measurements. Of the patients with comitant esodeviation, 6 had normal abduction OU (two after recovery from bilateral sixth nerve palsies), and 6 had mild or minimal abduction deficits. Moderate or severe abduction deficits were associated with incomitant measurements.

CONCLUSIONS

Comitant esodeviation can be common in children with identifiable neurologic insults.

[Inhibitory effect of 2-(N-acetyl-methyl amino)-3',4'-methylenedioxyacetyl-aminophene(SY-640) on covalent binding of carcinogenic benzo(a)pyrene with mouse hepatocyte nuclear DNA]

Many carcinogens must be first transformed into electrophilic ultimate carcinogens via metabolic activation in liver microsomes before covalent binding to nucleophilic center of DNA. SY-640 is a synthetic compound with hepatoprotective activity. Results of the present study indicate that the covalent binding of 3H-benzo(a)pyrine to mouse hepatocyte nuclear DNA in vitro and in vivo was markedly inhibited by SY-640. Further studies found that the liver microsomal cytochrome P-450 content and aminopyrine demethylase activity were significantly increased in mice treated with SY-640 (150 mg.kg-1 p.o.) once daily for three days, while the hepatic microsomal aminopyrine demethylase activity was obviously inhibited two hours after oral administration of SY-640 150 mg.kg-1 in mice. The aminopyrine demethylase activity of liver microsomes from normal, PB- and 3-MC-treated mice was also significantly inhibited by the addition of SY-640 in vitro. When SY-640 was incubated with NADPH-reduced mouse liver microsomes, a metabolic-intermediate(MI) complex at 457 nm was formed. The effects of SY-640 on cytochrome P-450 and its formation of MI complex with cytochrome P-450 may partially explain why SY-640 could inhibit covalent-binding of BP to mouse hepatocyte DNA in vitro.

Human articular cartilage biomechanics of the second metatarsal intermediate cuneiform joint

Intrinsic material properties and histomorphometry of freshly frozen, human cadaveric cartilage from the second metatarsal intermediate cuneiform (SMIC) articulation were obtained to provide biomechanical mapping of the surfaces. The biphasic creep indentation methodology and an automated creep indentation apparatus were used to measure aggregate modulus, Poisson's ratio, permeability, shear modulus, and thickness. Biomechanical experiments were performed on four sites of the SMIC joint in 14 specimens (seven pairs): two sites in the second metatarsal base and two sites in the intermediate cuneiform head. Results of the study indicate that no significant variations exist in the biomechanical comparisons between specific articulations, gross articulations, and left and right joints. For example, cartilage from the second metatarsal base and intermediate cuneiform head had an aggregate modulus of 0.99 MPa and 1.05 MPa, respectively. The Poisson's ratio and permeability of all test sites grouped together were found to be 0.08 and 3.05 x 10(-15) m4/N.s, respectively. Cartilage thickness was measured at 0.61 mm. This biomechanical study suggests that similarities in cartilage properties may be beneficial in preventing the human SMIC articulation from developing early degenerative changes. Histological evaluation demonstrated that SMIC cartilage exhibits structural characteristics (such as the absence of chondrocyte columnar arrangement in the deep zone) which may be typical of cartilage that does not experience habitually high compressive stresses. This knowledge could aid surgeons in generating a deeper perspective of the relationship between clinical pathologies of articular cartilage and intrinsic biomechanical etiologies of degenerative joint diseases.

[Protective action of corynoline, acetylcorynoline and protopine against experimental liver injury in mice]

Oral administration of two doses of corynoline, acetylcorynoline or protopine at 50 and 100 mg.kg-1 in an interval of 8 to 24 h before i.p. injection of CCl4, acetaminophen or thioacetamide significantly impeded the elevation of serum transaminase (SGPT) and liver damage in mice. The three compounds were found to inhibit CCl4-induced microsomal lipid peroxidation and CCl4 conversing to carbon monoxide in liver microsomes in vitro. Of these compounds, acetylcorynoline was shown to be more potent than corynoline and protopine. In addition, all the three compounds exhibited biphasic effects on the hepatic cytochrome P450, i.e. inhibition followed by induction, in mice.

[Effects of 16 drugs on immunological liver injury induced by BCG + lipopolysaccharides in mice]

AIM

To evaluate anti-hepatitis drugs.

METHODS

Mice were injected i.v. with viable BCG 5 x 10(7) (live) bacilli/mouse, after 10 d, i.v. lipopolysaccharides (LPS) 5-10 micrograms/mouse. Serum aminotransferase levels and liver tissue were examined 10 h after i.v. LPS. Sixteen drugs were evaluated in this model.

RESULTS

The level of AlaAT and AspAT were increased markedly. Submassive necrosis and infiltrations of granulocytes and lymphocytes were seen, which were not recovered till 14 d after i.v. LPS. Administration of interferon alpha-2a, Ara-AMP, hepatocyte growth factor, biphenyl dimethyl dicarboxylate, bicyclol, prednisolone, and cyclophosphamide for 10 d prior to i.v. LPS suppressed the elevation of serum AlaAT and AspAT.

CONCLUSION

The model of immunological liver injury reproduced by i.v. BCG + LPS in mice may be used for evaluating anti-hepatitis drugs.

Influences of Kupffer cell stimulation and suppression on immunological liver injury in mice

AIM

To study the possible involvement of Kupffer cells (KC) in immunological liver injury in mice.

METHODS

Liver injury was induced by i.v. injection of Bacillus Calmette-Guerin (BCG) 5 x 10(7) viable bacilli followed by i.v. injection of lipopolysaccharides (LPS) 7.5 micrograms to each mouse. Indian ink and silica were i.v. injected to suppress KC and retinol was given po to stimulate KC in these mice. Plasma alanine aminotransferase (AlaAT), aspatate aminotransferase (AspAT), nitric oxide (NO), and liver tissue were examined.

RESULTS

Injection of LPS following BCG injection resulted in a remarkable elevation of plasma NO, AlaAT, and AspAT levels, and severe liver damage. The damages were enhanced by the activation of KC with retinol and reduced by suppression of KC with silica and Indian ink.

CONCLUSION

The degree of liver injury induced by BCG + LPS is closely correlated with the status of KC, and NO from KC plays an important role in the pathogenesis of the liver damage in mice.