Ronald A. Rauch

Risk factors accelerating cerebral degenerative changes, cognitive decline and dementia

Factors accelerating cerebral degenerative changes represent potentially modifiable risks for cognitive decline. Putative risk factors accelerating subtle cognitive decline and dementia were correlated with repeated measures of cerebral atrophy, CT densitometry, perfusions and cognitive testing among neurologically and cognitively normative ageing volunteers.

Cardiovascular and Other Risk Factors for Alzheimer's Disease and Vascular Dementia

Abstract: Factors accelerating cerebral degenerative changes represent potentially modifiable risks for cognitive decline. Putative risks accelerating subtle cognitive decline and dementia were correlated with repeated measures of cerebral atrophy, CT densitometry, perfusions, and cognitive testing among 224 neurologically and cognitively normative aging volunteers. After age 60, cerebral atrophy, ventricular enlargement, polioaraiosis, and leukoaraiosis geometrically increased as perfusions declined. Risks accelerating perfusional decline, cerebral atrophy, polioaraiosis, and leukoaraiosis were: transient ischemic attacks (TIAs), hypertension, smoking, hyperlipidemia, male gender. At age 71.5 ± 11.9, subtle cognitive decline began, accelerated by TIAs, hypertension, and heart disease. Leukoaraiosis began before cognitive decline. TIAs, hypertension, and hyperlipidemia correlated with vasciular dementias. Excessive cortical perfusional decreases and cerebral atrophy correlated with cognitive decline. Family history of neurodegenerative disease correlated with Alzheimers disease. We concluded that TIAs, hypertension, hyperlipidemia, smoking, and male gender accelerate cerebral degenerative changes, cognitive decline, and dementia.

Parkinsonism due to Manganism in a Welder

A 33-year-old right-handed male presented complaining of a 2-year history of progressive cognitive slowing, rigidity, tremors, slowing of movements, and gait instability leading to falls. On examination, he had a Mini-Mental Status Examination (MMSE) score of 29, slowed saccadic eye pursuit, hypomimia, cogwheel rigidity, a 3- to 4-Hz tremor, and a “cock-walk” gait. His symptoms and signs were similar to idiopathic Parkinsons disease; however, he was young, inattention and forgetfulness occurred early in the course of the disorder, levodopa was unhelpful, and his gait was atypical. His work up for secondary causes of parkinsonism was negative, except for increased signal intensity on T1-weighted magnetic resonance image (MRI) in the bilateral basal ganglia. Typical etiologies for that finding were ruled-out, which led to further inquiries into the patients lifestyle. He was a welder, and discussion with his employer revealed that he used a steel-manganese alloy, he often worked in a confined ships hold, and he did not use a respiratory mask. Because manganese toxicity can produce increased T1-weighted signal intensities in the basal ganglia, the authors tested his serum and urine manganese, and both were elevated. This patient emphasizes the importance of a careful occupational history in persons presenting with atypical manifestations of a neurodegenerative disorder. It also lends support to the hypothesis that welding can produce enough exposure to manganese to produce neurologic impairment.

Altered brain activation during cognitive control in patients with moderate to severe traumatic brain injury.

Background. Persistent deficits in cognitive control have been documented following traumatic brain injury (TBI) but are inconsistently related to the presence and location of focal lesions. Objective. Functional magnetic resonance imaging (fMRI) was used to examine brain activation during a cognitive control task in patients with moderate to severe TBI or orthopedic injury (OI). Methods. Fourteen TBI patients and 10 OI patients underwent fMRI at 3 months postinjury using a stimulus-response compatibility task in which response accuracy and reaction time were measured. Performance between the groups was equated by individually adjusting the amount of training. Groups did not differ in age, gender, or education. Results. Brain activation during stimulus-response incompatibility was greater in TBI patients than in OI patients within the cingulate, medial frontal, middle frontal, and superior frontal gyri. However, the positive regression of activation with response accuracy during stimulus-response incompatibility indicated a stronger relationship for OI patients than the TBI group within the anterior cingulate gyrus, medial frontal, and parietal regions, as well as deep brain structures (eg, brainstem). The number of focal lesions within either the whole brain or within prefrontal areas was not related to brain activation, but there was a relationship between activation and TBI severity. Conclusions. These findings suggest that neural networks mediating cognitive control are altered after moderate to severe TBI, possibly as a result of diffuse axonal injury, and that the typical relationship of brain activation to performance is disrupted.

Ganglioglioma and Gangliocytoma

These are neuroepithelial tumors composed of mature neurons (gangliocytoma) or a mixed population of ganglion cells and glial cells (ganglioglioma). Well differentiated gangliocytomas are classified as WHO grade I while gangliogliomas may be classified as WHO grade I or II. Anaplastic ganglioglioma with a malignant glial component is classified as WHO grade III. Gangliogliomas and gangliocytomas may occur in all age groups but they are frequently seen in the young with a peak between the age of 10 and 30 years and representing about 0.4% of all tumors in the central nervous system.

Frontal MRI findings associated with impairment on the Executive Interview (EXIT25).

Abstract We examined the association between the Executive Interview (EXIT25), a bedside measure of executive control, and regional magnetic resonance imaging (MRI) pathology among 52 consecutive geriatric patients presenting to a university dementia assessment clinic. Left frontal (p < .002), left medial (p < .03), right frontal (p < .02), and right medial (p < .02) cortical lesions significantly worsened EXIT25 scores, even after adjusting for age, global cognitive impairment (on the Mini-Mental State Examination), and the severity of cortical dementia on the Qualitative Evaluation of Dementia [QED]. The EXIT25s associations with right hemisphere lesions did not persist after adjusting for left frontal lesions. Left posterior lesions did not significantly affect the EXIT25. Similarly, left frontal circuit pathology worsened EXIT25 scores (p < .05). Pathology in left anterior subcortical structures showed a trend (p = .052). EXIT25 scores were not affected by right subcortical pathology, nor by pathology in either hippocampus. We conclude that the EXIT25 is specifically affected by frontal system MRI lesions, particularly on the left. This conclusion is consistent with earlier functional neuroimaging studies associating EXIT25 performance with left mesiofrontal perfusion.

Disseminated Actinomyces meyeri infection resembling lung cancer with brain metastases.

Thoracic actinomycosis can resemble bronchogenic carcinoma in its clinical presentation and radiographic appearance. We report a case of pulmonary actinomycosis caused by Actinomyces meyeri in which hematogenous dissemination caused multiple brain abscesses resembling metastatic lung cancer. The correct diagnosis was made by thin-needle aspiration of a pleura-based lung mass. The pathogen isolated was further identified with the use of 16S rDNA sequencing. Antibiotic therapy resulted in rapid improvement of the lung lesion; however, the brain lesions required surgical drainage. Antibiotics were continued for more than a year before magnetic resonance images showed complete resolution of the cerebral abscesses.

Central Neurocytoma and Extraventricular Neurocytoma

A low-grade (WHO 2007, grade II) ventricular (central neurocytoma) or extraventricular tumor composed of a monomorphic population of uniform round neurocytic cells. More common in the lateral and third ventricles but may occur in the fourth ventricle and extraventricular sites including the cerebral hemispheric parenchyma and spinal cord. Occurs predominantly in young adults with a peak incidence in the third and fourth decades, and with a low incidence in the first and second decades.

Age-related cerebrovascular disease alters the symptomatic course of migraine

Migraine headaches usually decrease in frequency and severity and often cease during advancing age. Occasionally, migraineurs report late-life migrainous accompaniments, i.e., auras without headache, particularly when typical migraine attacks terminate or diminish following major or minor strokes, at which time the auras may become atypical. Clinical observations such as these suggest that degenerative cerebrovascular changes accompanying aging may modify the course of migraine headaches particularly those with aura. To test this hypothesis, we quantitated age-related changes in cerebral vasodilator capacitance by measuring local cerebral blood flow utilizing xenon contrast computed tomography (CT) scanning before and after oral administration of the pharmacological cerebral vasodilator, acetazolamide (Diamox®). Measurements were compared among 27 normal volunteers without headache (aged 24–94 years; mean age 61.1 ± 17.6) and 37 carefully categorized groups of migraine patients (aged 27–83 years; mean age 59.4 ±12.4). The normals comprised Group A. Migraineurs were divided into two subgroups: Group B consisted of 27 migraineurs with and without aura who continued to suffer from incapacitating and frequent headaches and Group C consisted of 10 migraineurs who no longer suffered from severe and frequent headaches, two of whom still complained of atypical auras of the “late-life migrainous accompaniments” type. Cerebral vasodilator capacitance significantly declined with advancing age among normals and the two groups of migraineurs, confirming the development of age-related cerebrovascular diseases. Global CBF increases after Diamox® in Group B (with persistent and severe migraine), were significantly greater compared with normals without headache, and with Group C consisting of migraineurs whose headaches had decreased, subsided, or become replaced by late-life migrainous accompaniments (Group C). Results establish that cerebrovasodilator capacitance declines with advancing age, probably due to progressive cerebral atherosclerosis, since these declines were accentuated by risk factors for stroke, particularly TIAs or documented lacunar infarcts by CT. Progressive impairments of cerebral vasodilator capacitance among migraineurs were associated with: (i) reductions in frequency and severity of migrainous cephalalgia and (ii) appearance of late-life migrainous accompaniments.

The Emergence of Zoonotic Onchocerca lupi Infection in the United States – A Case-Series

This case-series describes the 6 human infections with Onchocerca lupi, a parasite known to infect cats and dogs, that have been identified in the United States since 2013. Unlike cases reported outside the country, the American patients have not had subconjunctival nodules but have manifested more invasive disease (eg, spinal, orbital, and subdermal nodules). Diagnosis remains challenging in the absence of a serologic test. Treatment should be guided by what is done for Onchocerca volvulus as there are no data for O. lupi. Available evidence suggests that there may be transmission in southwestern United States, but the risk of transmission to humans is not known. Research is needed to better define the burden of disease in the United States and develop appropriately-targeted prevention strategies.