Search PubMed⌕ Search

Biomedical subjects

P J Koehler

Publications and source records attributed to P J Koehler.

At least 19 recordsLinked to original sources
PubMed2006

[The significance of Bernard Brouwer's contribution to Dutch neurology and neurosurgery. On the 125th anniversary of the year of his birth].

Following his training under Winkler and carrying out research at the Central Institute for Brain Research in Amsterdam, in 1923 Bernard Brouwer (1881-1949) became the firstprofessor ofneurologyindependent from psychiatry, in the Netherlands. His most important scientific work included comparative anatomical studies of the cerebellum and the projection of retinal fibres on the geniculate body and occipital cortex. He gained international fame and in 1926, during one of his American lecture tours, he was invited to fill the new chair of experimental neurology at Johns Hopkins University. He refused this offer and instead started a new university clinic for neurology in Amsterdam, which included neurosurgery. He did however send a surgeon--Dr. Oljenick--to America to be trained by Cushing. The Amsterdam neurology clinic became an international exchange centre for students of neuroscience. The difficult decisions he had to make during his rectorate in the Second World War, were criticised in 1945. During the last years of his life, he was director of the Central Institute for Brain Research.

History, 19th Century↗
PubMed2006

[From gene to disease; the PABN1 gene and oculopharyngeal muscular dystrophy].

Oculopharyngeal muscular dystrophy is a rare disease, presenting with bilateral ptosis and dysphagia, followed by slow progressive muscle weakness. The pathological hallmark of the disease is the presence of intranuclear inclusions in muscle cells. Inheritance is autosomal dominant in almost all cases. The mutation responsible is a short guanine-cytosine-guanine (GCG) expansion in the 'poly adenylate binding nuclear I protein' (PABN1) gene. This expansion is stable in subsequent generations and is translated into a polyalanine tract. The aberrant protein is found within the intranuclear inclusions and interferes with normal mRNA function.

Blepharoptosis↗
PubMed2006

[Diagnostic image (270). A confused and restless woman].

A 63-year-old woman suffering from confusion, restlessness, vertigo and nausea had multiple old cortical and subcortical microhaemorrhages on MR gradient echo imaging, consistent with amyloid angiopathy.

Cerebral Amyloid Angiopathy↗
PubMed2006

[The practice guideline 'Headache' from the Dutch College of General Practitioners; a response from the perspective of neurology].

In comparison with the previous version, the Dutch College of General Practitioners' practice guideline 'Headache' has been improved in several respects. The addition of information on cluster headache, tension headache and substance-induced headache may benefit the daily practice of the general practitioner. The list of alarm symptoms is useful for distinguishing between secondary and primary types of headache. With respect to substance-induced headache, there is a difference from the international criteria: according to the latter, the diagnosis may also be made if the headache does not completely disappear but reverts back to the previous pattern. There is a need for studies into the non-medicinal treatment of tension headache. In these practice guidelines, the medicinal treatment of migraine is largely consistent with the guidelines of The Netherlands Society of Neurology.

Diagnosis, Differential↗
PubMed2005

[Balance disorder and subacute hydrocephalus due to haemorrhage in a cerebral cavernous malformation].

A 58-year-old man presented with a balance disorder, followed by progressive memory disturbance, urinary incontinence and vomiting. MRI of the brain revealed multiple cavernous malformations, with recent haemorrhage from one of them, in the brainstem, causing a hydrocephalus. After treatment for the hydrocephalus, the symptoms resolved quickly. Cerebral cavernomas may cause epileptic seizures, haemorrhaging and progressive neurological deficits. Diagnosis is on the basis of the typical MRI pattern of a hyperintense core, surrounded by a hypointense rim of old blood. Treatment consists of surgery if the lesion is easily accessible and can be completely removed. Other options are gamma-knife surgery, stereotactic radiotherapy and conservative treatment.

Cavernous Sinus↗
PubMed2004

Associations with autoimmune disorders and HLA class I and II antigens in inclusion body myositis.

Whether autoimmune mechanisms play a role in the pathogenesis of inclusion body myositis (IBM) is unknown. Human leukocyte antigen (HLA) analysis in 52 patients, including 17 with autoimmune disorders (AIDs), showed that patients were more likely to have antigens from the autoimmune-prone HLA-B8-DR3 ancestral haplotype than healthy control subjects, irrespective of the presence of AIDs. Patients lacked the apparently protective HLA-DR53 antigen. The results provide further support for an autoimmune basis in IBM.

Age of Onset↗
PubMed2004

Important observations prior to the description of the Hoover sign.

OBJECTIVE: To study the context in which Hoover described his sign for differentiating hysterical and organic hemiplegia. BACKGROUND: At the turn of the 20th century, many physicians were looking for signs to distinguish organic from hysterical hemiparesis. In 1908, Hoover described his sign of "complementary opposition." Other signs based on associated movements of the upper extremities, lower extremities, and trunk were also described during and before this period and might have contributed to Hoover's understanding of complementary opposition. METHODS: A complete literature review of the original relevant articles by Babinski, Bychowski, Grasset and Gaussel, and Hoover was performed. RESULTS: Several similar maneuvers were described before the Hoover sign. Babinski described the trunk-thigh test in 1897. Bychowski in Warsaw (performed since 1902, published in 1907) and Grasset and Gaussel in Paris (1905) independently described a phenomenon in which the separate elevation of each leg was performed more easily than simultaneous elevation. Moreover, Bychowski, although not emphasizing it as a sign, described what became known as Hoover sign. Hoover sign (1908) has been considered a further elaboration of these previous observations. Interestingly, Hoover had studied in Europe, and although no direct relationship between his discovery and these observations has been elucidated, the authors postulate that he was influenced by Babinski, Bychowski, and Grasset and Gaussel. CONCLUSION: Although Babinski, Bychowski, and Grasset and Gaussel described similar signs, only Hoover sign is still in wide use by practitioners.

Hemiplegia↗
PubMed2004

The relevance of intraventricular chemotherapy for leptomeningeal metastasis in breast cancer: a randomised study.

To assess the benefit of intraventricular chemotherapy, patients with leptomeningeal metastasis (LM) from breast cancer were randomised to treatment including intraventricular (IT) chemotherapy (n=17) or to non-intrathecal (non-IT) treatment (n=18). Appropriate systemic therapy and involved field radiation therapy (RT) were given in both arms. Intention-to-treat analysis showed neurological improvement or stabilisation in 59% of the IT and in 67% of the non-IT group, with median time to progression of 23 weeks (IT) and 24 weeks (non-IT). Median survival of IT patients was 18.3 weeks and 30.3 weeks for non-IT patients (difference 12.9 weeks; 95% Confidence Interval (CI) -5.5 to +34.3 weeks; P=0.32). Neurological complications of treatment occurred in 47% (IT) vs 6% (non-IT) (P=0.0072). In conclusion, standard systemic chemotherapy with involved field RT for LM from breast cancer is feasible. Addition of intraventricular chemotherapy does not lead to survival benefit or improved neurological response, and is associated with an increased risk of neurotoxicity.

Adult↗
PubMed2003

[The Dutch College of General Practitioners' practice guideline "Dizziness"; reaction from a neurologic perspective].

When a patient complains of dizziness, the term may cover several types of sensations. When the physician carefully takes the history, he or she will most often be able to differentiate between vertigo and other types of dizziness, including a feeling of lightness or fainting. Based on this differentiation, the Dutch College of General Practitioners (NHG) designed a practice guideline for its members. The most important causes of vertigo are paroxysmal benign positional vertigo, vestibular neuritis, Ménière's disease and TIA or stroke in the vertebrobasilar system. Differentiation between vestibular neuritis and stroke may be difficult, in particular at the onset of the complaints and therefore consultation of a neurologist will often be necessary. Fortunately, special drugs for dizziness are not recommended, as their effectiveness has not been proven. Among the causes of non-vertigo dizziness complaints, hyperventilation, often in the context of anxiety disorder, is a major cause. In general, the NHG succeeded in compiling a practical guideline.

Diagnosis, Differential↗
PubMed2003

[A child with peculiar movements: Sydenham chorea].

An 11-year-old girl with Sydenham chorea presented with a rapid onset of serious restlessness of mainly the right side of the body. Additional laboratory investigations revealed no abnormalities, yet this is not unusual for such cases. Valproic acid and pimozide were then successively prescribed because of the chorea. For secondary prevention she received long-term oral penicillin. Sydenham chorea is a manifestation of rheumatic fever and occurs after a throat infection by group A streptococci. The disease is characteristic and consists of a combination of choreic movements, hypotonia and emotional lability. The clinical course is diverse. Improvement usually occurs over a period of several months, although a significant proportion of patients exhibit little recovery.

Anti-Dyskinesia Agents↗
PubMed2002

Visual cortex excitability in migraine before and after valproate prophylaxis: a pilot study using TMS.

We examined the effect of standard migraine prophylaxis with sodium valproate on repeated measures of occipital excitability using transcranial magnetic stimulation (TMS). We predicted that, comparing pre- and post-treatment assessments, a reduction in clinical migraine parameters would be paralleled by a decrease in excitability measurements.A total of 31 migraine patients enrolled in the study, for assessment prior to and 1 month after commencement of sodium valproate prophylaxis. At each assessment, we used a standardized protocol to stimulate the occipital cortex with a 90-mm circular (coil A) and 70 mm figure-of-eight (coil B) coil. We recorded the threshold stimulation intensity at which subjects just perceived phosphenes. Subjects kept detailed records of headache parameters 1 month before and also during the study period. Valproate therapy significantly improved headache indexes, as expected. In MA subjects assessed with coil B, phosphene thresholds were significantly higher post-treatment than pre-treatment, but those for MO did not change. Modest correlations were observed in MA patients between increase in phosphene threshold and decrease in headache index. Although preliminary, the findings with coil B lend some support to the notion that effective migraine prophylaxis may be achieved through lowering cortical excitability by gamma-aminobutyric acid (GABA)-ergic intervention. Further investigation of the effect of sodium valproate or other similarly acting substances on cortical excitability in migraine is warranted.

Anticonvulsants↗
PubMed2002

The early use of ergotamine in migraine. Edward Woakes' report of 1868, its theoretical and practical background and its international reception.

Although ergot had been used in obstetrics for several centuries, it was proposed for the treatment of migraine only in the 19th century. The British ENT-surgeon Edward Woakes (1837-1912) recommended ergot as a vasoconstricting agent for migraine and other neurogenic conditions associated with vasodilatation in 1868. He subscribed to the theory of vasodilatation by sympathetic deficit, presented in the early 1850s by Brown-Séquard and Claude Bernard. Du Bois-Reymond proposed vasoconstriction by sympathetic overactivity as the cause of migraine in 1860; Brown-Séquard opposed this in favour of vasodilatation. Vasodilatation due to sympathetic deficit in migraine was again supported by Möllendorf, with clinical evidence, in 1867. Woakes' paper of 1868 introduced ergot as a vasoconstrictor for the same condition. Reception abroad was prompt. A German version appeared in 1869, and Eulenburg cited Woakes in his textbook of 1871. Eulenburg presented the use of ergot for migraine as a routine measure in the second edition of his textbook in 1878, and in a paper published in 1883. The method was internationally accepted, but it became really popular only after the isolation of pure ergotamine in 1918, resulting in the first reliable compounds with stable properties and predictable effects. Contrary to Woakes' theory, in the early 20th century ergot was used for migraine because of its well-documented adrenolytic properties, as migraine was by then again believed to be a sympathotonic and vasospastic condition.

England↗