Effects of visual pathway lesions on the visual aura of migraine.

The aim was to to determine if the visual aura of migraine is altered by disease of the afferent visual pathways and if visual aura changes are associated with pre- or postgeniculate lesions. Functional neuroimaging during migraine demonstrates primary visual/extrastriate cortex as an anatomical substrate of visual aura. Neuro-ophthalmological records (including kinetic and static perimetry) of 25 patients with visual loss and typical aura with or without migraine headache were reviewed. Twenty-five patients (16 women, nine men) (mean age 59.8 years) with typical aura had visual loss from pregeniculate (72%) or postgeniculate lesions (28%). Eight patients (four postgeniculate cerebrovascular accidents or arteriovenous malformations, two lifelong optic neuropathy/retinopathy, one childhood ocular trauma, one anisometropic amblyopia) reported absence or alteration of visual aura. Postgeniculate lesions were significantly associated (P = 0.017) with visual aura changes. The association of postgeniculate lesions with altered auras points to a postgeniculate effect on aura appearance (consistent with functional neuroimaging findings). Although statistically significant, this series' association of postgeniculate disease and aura changes is even more robust (P = 0.0002) when structural changes of ocular dominance columns are posited in three patients with optic neuropathy, retinopathy and keratopathy of congenital or childhood origin.

Disorders of ocular motility following head trauma.

OBJECTIVE: To determine the types and frequency of symptomatic ocular motility disturbances following head trauma and their association with severity of trauma. DESIGN: Retrospective study of patients with (1) diplopia unless visual loss is present, (2) heterotropia for far or near targets, and (3) prior head injury. SETTING: Office and in-hospital consulting practice of a university neuro-ophthalmologist. SUBJECTS: Sixty patients with posttraumatic ophthalmoplegia. MAIN OUTCOME MEASURES: Paralytic and nonparalytic heterotropias were quantitated in prism diopters or percentage limitation of ductions. Convergence insufficiency was assessed by determining the near point of convergence. RESULTS: Fifty-one patients had nuclear or infranuclear findings, ie, trochlear palsies (n = 20), oculomotor palsies (n = 17), abducens palsies (n = 7), combined palsies (n = 5), and restrictive ophthalmopathy (n = 2). Nine patients had supranuclear dysfunction, including seven patients with convergence insufficiency. Bilateral ocular motor palsies and combined palsies were significantly (by means of chi 2 test) associated with head trauma of severity sufficient to cause corticospinal tract dysfunction. Individual or combined ocular motor palsies were not significantly (by means of chi 2 test) associated with intracranial hemorrhage and/or skull fracture or loss of consciousness. CONCLUSIONS: Trochlear palsy was the most common nuclear or infranuclear basis for traumatic diplopia, and convergence insufficiency was the most common supranuclear cause of double vision. Head trauma distinguished by upper motor-neuron signs was correlated with specific subsets of disordered ocular motility.

Harvey Cushing, Gordon Holmes, and the neurological lessons of World War I.

As the gunshots that fatally wounded Archduke Franz Ferdinand and Countess Sophie of Austria resounded from Sarajevo across Europe to become the deafening roar of artillery on the Western Front in August 1914, Harvey Williams Cushing was the world's preeminent neurosurgeon and Gordon Morgan Holmes was arguably the foremost neurologist in the world. The 45-year-old Cushing, and Holmes just 38 years old, would strive to respond to the neurological challenges of World War I. They distinguished themselves amidst the redoubtable efforts of workers such as Walter Cannon, George Riddoch, Charles Sherrington, Henry Head, Victor Horsley, Walther Poppelreuter, and Robert Barany. Even the intense martial spirit of the time would be held in abeyance by the contributions of such men of science, as when the intercession of Prince Carl of Sweden secured the release of Barany from a Russian prisoner-of-war camp and allowed him to accept the 1916 Nobel Prize for his exposition of vestibular physiology. Such respite from the brutality of war was all too brief, and if we are to grasp the significance of the different approaches of Holmes and Cushing to the terrible problems of World War I, we must examine some of the harsh medical realities that they confronted in the "war to end all wars."

The origin of pain in optic neuritis. Determinants of pain in 101 eyes with optic neuritis.

In 101 eyes with either anterior or retrobulbar optic neuropathy of ischemic or inflammatory origin, ocular pain occurred significantly more often with retrobulbar optic neuropathy. The association of pain with posterior optic nerve lesions supports Whitnall's hypothesis that the pain of optic nerve inflammation is caused by traction of the origins of the superior and medial recti on the optic nerve sheath at the orbital apex. Eye pain reflected neither severity nor origin of optic neuropathy.

Ataxic hemiparesis from lesions of the corona radiata.

Ipsilateral cerebellar and pyramidal signs suddenly developed in three patients. Computed tomography revealed small infarcts of the corona radiata in two patients and a small infarct in the posterior limb of the internal capsule in the third. Ataxic hemiparesis can result from lesions of the corona radiata as well as many other points along the corticopontine pathways.

Alcoholic myelopathy without substantial liver disease. A syndrome of progressive dorsal and lateral column dysfunction.

Five well-nourished, alcoholic patients had a progressive myelopathy. Symptoms began with paresthesias of the feet and progressed to a spastic paraparesis with clinical signs of both lateral and dorsal column involvement. Abstinence from alcohol halted progression but did not cause improvement in the myelopathy. The absence of portacaval shunting or notable liver dysfunction in these patients suggests that a direct toxic effect of alcohol must be considered a possible mechanism of spinal cord damage.

Unilateral and highly asymmetric papilledema in pseudotumor cerebri.

I compared six subjects with pseudotumor cerebri and unilateral or highly asymmetric papilledema with 20 such patients with bilateral papilledema. Patients with unilateral papilledema were significantly older than those with bilateral papilledema, but there were no significant differences between the two groups in disease duration, elevation of intracranial pressure, visual fields and acuity, and presence of headaches or transient visual obscurations. I hypothesize that, in patients with unilateral papilledema, one optic nerve is protected from pressure effects by optic nerve sheath anomalies or lamina cribrosa changes due to increased collagen and decreased elasticity with aging.

The preserved temporal crescent: the clinical implications of an "endangered" finding.

Sixteen consecutive patients with a partially or completely preserved temporal crescent (PTC) in right or left eye were identified by Goldmann kinetic perimetry. PTC etiologies were stroke, birth injury, trauma, aneurysm, and migraine. PTC eludes detection by automated static perimetry of the central visual field, but its ascertainment with Goldmann perimetry usually implies contralateral occipital lobe ischemia sparing a small portion of anterior primary visual cortex.

Unilateral ptosis and Hering's law.

In 21 patients with unilateral ptosis, only 1 was found to have lid retraction of the fellow eye--a sign regarded as evidence of Hering's law of equal innervation governing levator function. Hering's law may influence levator function in select cases of ptosis due to disease at or distal to the neuromuscular junction. Alternatively, the relatively autonomous contraction of orbicularis oculi or inhibition of frontalis may mask unilateral lid retraction.

Bilateral cerebral ptosis.

We studied 13 patients with bilateral ptosis after acute right frontotemporoparietal lobe lesions. All patients had conjugate gaze deviation to the right. The ptosis persisted for about 5 days in five patients, or was still evident at the time of discharge or death. Other cranial nerve findings included lower facial weakness in five patients and both upper and lower facial weakness in eight patients. The transience of cerebral ptosis and conjugate gaze disturbance may imply ability of the intact hemisphere to assume control.

Spontaneous visual phenomena with visual loss: 104 patients with lesions of retinal and neural afferent pathways.

Fifty-seven percent of 104 consecutive patients with retinal or neural visual loss reported spontaneous visual phenomena (SVP). Elementary SVP occurred more commonly (51% of patients) than complex SVP (21%). SVP occur with lesions of any portion of the visual pathways. Unlike irritative hallucinations, they do not aid in localization of the lesion. SVP occur significantly more frequently with visual acuity of 20/50 or less in both eyes. These purely visual hallucinations are unlikely to herald psychiatric disease and may be release phenomena stemming from loss of inhibitory visual input.

Uhthoff's symptom in disorders of the anterior visual pathways.

To determine the frequency and clinical characteristics of Uhthoff's symptom, I studied 100 consecutive patients with pregeniculate visual loss of diverse etiology. Eighteen patients reported Uhthoff's symptom. Although there was a significant association of Uhthoff's symptom with multiple sclerosis (10 patients), other etiologies for this symptom included tumor (3 patients), optic neuropathy or papillitis (3 patients), aneurysm, and orbital pseudotumor (1 patient each). There was no link between the severity of visual loss, as measured by diminished acuity, field loss, or binocular involvement, and Uhthoff's symptom.

"Apraxia" of eyelid opening: an involuntary levator inhibition.

Apraxia of lid opening was described by Goldstein and Cogan as "a non paralytic motor abnormality characterized by the patient's difficulty in initiating the act of lid elevation." We studied six such patients with this finding accompanied by vigorous frontalis contraction and no evidence of ongoing orbicularis oculi contraction, dysfunction of the oculomotor nerve, or loss of ocular sympathetic innervation. Four patients had Parkinson's disease or atypical parkinsonism, one had progressive supranuclear palsy, and one had Shy-Drager syndrome. At onset of ocular symptoms, mean age was 64 years, and the mean duration of extrapyramidal symptoms was 9.7 years. By definition, the motor system must be intact in any apraxia. Therefore, this disorder of lid opening in patients with extrapyramidal motor dysfunction is not an apraxia, but rather involuntary levator palpebrae inhibition of supranuclear origin.

Supranuclear disturbances of ocular motility in Lytico-Bodig.

We found abnormal supranuclear ocular or lid motility in all of 37 patients with Lytico-Bodig (amyotrophic lateral sclerosis/parkinsonism-dementia complex). Twenty-one patients had pursuit paresis, 18 abnormal vestibulo-ocular reflex (VOR) cancellation, 15 abnormal convergence, 13 abnormal optokinetic nystagmus (OKN), 12 conjugate gaze limitation, nine nystagmus, nine saccadic paresis, and six abnormal fixation. Lid abnormalities included glabellar hyperreflexia in 21, involuntary levator inhibition in three, and blepharospasm in two. Earlier reports have indicated infrequent ocular disturbances in Lytico-Bodig, but we now find supranuclear eye and lid deficits are universal and sometimes very prominent.

Follow-up study of risk factors in progressive supranuclear palsy.

The cause of progressive supranuclear palsy (PSP) is not known and has been little studied. The one previous controlled epidemiologic survey, performed at our center in 1986, found small-town experience and greater educational attainment as PSP risks, but, in retrospect, these results may have been produced by ascertainment bias. Since that time, several anecdotal reports have implicated heredity and various environmental exposures in the cause of some cases of PSP. To clarify the results of the previous study and to evaluate the more recently implicated candidate factors in a controlled fashion, we mailed a validated 69-item questionnaire to 91 personally examined patients with PSP and 104 unmatched controls with other neurologic conditions for which they had been referred to our tertiary neurologic center. We were able to match 75 subjects from each group by year of birth, sex, and race and subjected them to a separate matched-pair analysis. We allowed surrogates to supply any or all of the responses. Questions concerned hydrocarbon, pesticide, and herbicide exposure; urban/rural living; auto repair and other occupations; head trauma; educational attainment; maternal age; and family history of PSP, parkinsonism, dementia, and other neurologic conditions. A statistically significant finding was that patients with PSP were less likely to have completed at least 12 years of school (matched odds ratio = 0.35, 95% CI = 0.12-0.95, p = 0.022; unmatched odds ratio = 0.44, 95% CI = 0.21-0.89, p = 0.020). We hypothesize that this result may be a proxy for poor early-life nutrition or for occupational or residential exposure to an as-yet unsuspected toxin. Future studies should examine these potential risk factors in PSP.

Misdirection revisited. A critical appraisal of acquired oculomotor nerve synkinesis.

Two patients exhibiting "primary" oculomotor misdirection caused by intracavernous mass lesions, and a third boy with transient oculomotor synkinesis after migrainous ophthalmoplegia provide background for a reassessment of the currently accepted explanation of anomalous synkineses subsequent to oculomotor nerve palsies. The hypothesis of peripheral misdirection of regenerating motor axons is inconsistent with these clinical observations, and an alternate mechanism is suggested, based on concepts of ephaptic neuronal transmission of impulses or on chromatolysis-induced reorganization of nuclear synapses.

Bilateral internuclear ophthalmoplegia after intrathecal chemotherapy and cranial irradiation.

A 26-year-old man developed transient bilateral internuclear ophthalmoplegia with exotropia after cranial irradiation and intrathecal administration of methotrexate for lymphoma. Resolution of the ophthalmoplegia and the decrease in abnormally high levels of cerebrospinal fluid myelin basic protein after discontinuation of intrathecal medication suggested demyelination from chemotherapy and irradiation.

Neuro-ophthalmology according to Gordon Holmes.

Holmes' priority in establishing an extensive body of knowledge that defines much of neuro-ophthalmology is given. His original descriptions are reviewed and his findings reappraised in light of present-day knowledge.

Progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) was first recognized as a distinct morbid entity by Richardson, Steele and Olszewski a quarter century ago. Subsequent experience has confirmed and extended their original observations. PSP has become familiar as a chronic progressive disorder with extrapyramidal rigidity, bradykinesia, gait impairment, bulbar palsy, dementia and a characteristic supranuclear ophthalmoplegia. It is an important cause of parkinsonism. Its etiology remains obscure. Familial concentrations have not been observed. Some cases exhibit no oculomotor dysfunction. Dementia is usually mild. Recent neuropsychological studies have defined features consistent with frontal lobe cortical dysfunction. Seizures and paroxysmal EEG activity may occur. CT and MRI scans show midbrain atrophy early and later atrophy of the pontine and midbrain tegmentum and the frontal and temporal lobes. PET scans have shown frontal hypometabolism and loss of striatal D-2 dopamine receptors. Postmortem studies have documented involvement of both dopaminergic and cholinergic systems. Treatment remains palliative and unsatisfactory.

Visual fields and tiagabine: a quandary.

This case report describes the development of asymptomatic visual field defects (VFDs) in a psychiatric patient with bipolar disorder receiving adjunctive tiagabine treatment. These defects were apparently reversible upon the discontinuation of tiagabine. Controlled clinical trials are indicated to determine if this finding is indicative of a class effect for all GABAergic antiepileptic drugs (AEDs), as already noted with vigabatrin, or if this case represents an incidental finding with tiagabine (41 references).