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Biomedical subjects

H L Hamburger

Publications and source records attributed to H L Hamburger.

18 recordsLinked to original sources
PubMed2005

Short-term effects of a mandibular advancement device on obstructive sleep apnoea: an open-label pilot trial.

Obstructive sleep apnoea (OSA) is a common sleep disorder, which is, among others, associated with snoring. OSA has a considerable impact on a patient's general health and daily life. Nasal continuous positive airway pressure (nCPAP) is frequently used as a "gold standard" treatment for OSA. As an alternative, especially for mild/moderate cases, mandibular advancement devices (MADs) are prescribed increasingly. Their efficacy and effectiveness seem to be acceptable. Although some randomized clinical trials (RCTs) have been published recently, most studies so far are case studies. Therefore, our department is planning a controlled RCT, in which MADs are compared with both nCPAP and a control condition in a parallel design. As a first step, an adjustable MAD was developed with a small, more or less constant vertical dimension at different mandibular positions. To test the device and the experimental procedures, a pilot trial was performed with 10 OSA patients (six mild, four moderate; one women, nine men; mean age = 47.9 +/- 9.7 years). They all underwent a polysomnographic recording before as well as 2-14 weeks after insertion of the MAD (adjusted at 50% of the maximal protrusion). The apnoea-hypopnoea index (AHI) was significantly reduced with the MAD in situ (P = 0.017). When analysed as separate groups, the moderate cases showed a significantly larger decrease in AHI than the mild cases (P = 0.012). It was therefore concluded from this pilot study that this MAD might be an effective tool in the treatment of, especially, moderate OSA.

Adult↗
PubMed2004

Craniomandibular pain, oral parafunctions, and psychological stress in a longitudinal case study.

In a single case study, the most frequently suggested contributing factors to craniomandibular pain, viz., oral parafunctions and psychological stress, were studied in more detail. During a 13-week study period, questionnaires were completed, in which, among others, jaw muscle pain, bruxism behaviour, and experienced/anticipated stress were noted. During about 40% of the nights, nocturnal masticatory muscle activity (NMMA) was recorded, using single-channel electromyography (EMG). The number of NMMA events per recorded hour was scored, using a detection threshold of 10% of the maximum voluntary contraction level. This threshold was established in a separate study, in which EMG was compared with polysomnography. Stepwise regression analyses indicated, that morning jaw muscle pain could be explained by evening jaw muscle pain for 64% and by alcohol intake for another 2%. In turn, evening jaw muscle pain was explained by daytime clenching for 56% and by vacuum sucking of the tongue for an additional 6%. Finally, daytime clenching was significantly explained by experienced stress for 30%. Data of the recorded nights showed, that variations in NMMA did not contribute to variations in morning jaw muscle pain. This case study corroborates the paradigm that experienced stress may be related to daytime clenching and, in turn, to evening and morning jaw muscle pain.

Electromyography↗
PubMed2001

Neurophysiological evaluation of late effects of adjuvant high-dose chemotherapy on cognitive function.

OBJECTIVES: To evaluate late neurotoxicity of adjuvant high-dose (HD) chemotherapy versus standard-dose (SD) chemotherapy by event-related potentials (ERP) and quantitative electroencephalography (qEEG). PATIENTS AND METHODS: From a randomized study in high-risk breast cancer patients on the efficacy of high-dose versus standard-dose adjuvant chemotherapy, late effects on cognitive functioning were analyzed by neuropsychological tests. Cognitive impairment was found in 32% of the HD group, 17% of the SD group and in 9% of a control group of stage I breast cancer patients not treated with chemotherapy. In 17 consecutive patients in the HD group and 16 consecutive patients in the SD group neurophysiological tests were performed, consisting of P300 and qEEG. Results of patients treated with chemotherapy were compared with results of 14 control patients not treated with chemotherapy. All patients were tested two years after treatment. RESULTS: Asymmetry of the alpha rhythm of > or =0.5 Hz was found in 7 HD patients, 2 SD patients and in none of the control patients (p = 0.01). No differences were found between the groups with regard to frequency of alpha rhythm, alpha blocking and latency of P300. No correlation was found between neurophysiological parameters and neuropsychological performance, except for an overall relation between the P300 latencies and the total number of deviant test scores. CONCLUSION: Although the neurophysiological differences are subtle and the relation with the cognitive functioning in individual patients as measured by the neuropsychological examination is equivocal, the results suggest that there is neurophysiological support for cognitive dysfunction as a late complication of high-dose systemic chemotherapy in breast cancer.

Alpha Rhythm↗
PubMed2001

Outcome of cervical spine surgery in patients with rheumatoid arthritis.

OBJECTIVES: Cervical spine instability in patients with rheumatoid arthritis (RA) may lead to cervical myelopathy or occipital neuralgia, or both. Morbidity and mortality in patients with RA treated with cervical spine surgery during two years of follow up were evaluated. METHODS: Between 1992 and 1996 55 patients with RA underwent cervical spine surgery because of occipital neuralgia or cervical myelopathy, or both. Patients were classified according to the Ranawat criteria for pain and neurological assessment before operation and three months and two years postoperatively. For occipital neuralgia a successful operation was defined as complete relief of pain and for cervical myelopathy as neurological improvement. RESULTS: Occipital neuralgia was present in 17 patients, cervical myelopathy in 14 patients, and 24 had both. Surgical treatment in the patients with symptoms of occipital neuralgia who were still alive two years after surgery was successful in 18/29 (62%). In the surviving patients with cervical myelopathy neurological improvement of at least one Ranawat class was seen in 16/24 (67%). Postoperative mortality within six weeks was 3/51 (6%). Within two years after the operation 14 /51 (27%) of the patients had died; in most patients the cause of death was not related to surgery. The highest mortality (50%) was found in the group of six patients with quadriparesis and very poor functional capacity (Ranawat IIIB). CONCLUSION: Cervical spine surgery in patients with RA performed because of occipital neuralgia or cervical myelopathy, or both, is successful in most patients who are alive two years after surgery. However, the mortality rate during these two years is relatively high, which seems to be largely related to the severity of the underlying disease and not to the surgery itself.

Adult↗
PubMed1998

Sleep apnoea caused by rheumatoid arthritis.

Sleep apnoea syndrome (SAS) is a rarely documented, but possibly lethal, complication of the instability of the cervical spine in rheumatoid arthritis. Five patients with SAS of a central or peripheral origin are presented, and the problems of recognizing and diagnosing the syndrome are discussed. We hope that clinicians will become more aware of the existence and the different aetiologies of SAS, thus improving early recognition and appropriate treatment. Adequate treatment has proven to increase survival in peripheral SAS and seems to be successful in doing so in central SAS.

Adult↗
PubMed1998

Cognitive complaints in patients after whiplash injury: the impact of malingering.

OBJECTIVES: The validity of memory and concentration complaints that are often reported after a whiplash trauma is controversial. The prevalence of malingering or underperformance in post-whiplash patients, and its impact on their cognitive test results were studied. METHODS: The Amsterdam short term memory (ASTM) test, a recently developed malingering test, was used as well as a series of conventional memory and concentration tests. The study sample was a highly selected group of patients, who were examined either as part of a litigation procedure (n=36) or in the normal routine of an outpatient clinic (n=72). RESULTS: The prevalence of underperformance, as defined by a positive score on the malingering test, was 61% (95% CI: 45-77) in the context of litigation, and 29% (95% CI: 18-40) in the outpatient clinic (p=0.003). Furthermore, the scores on the memory and concentration test of malingering post-whiplash patients (n=43) and non-malingering post-whiplash patients (n=65) were compared with the scores of patients with closed head injury (n=20) and normal controls (n=46). The malingering post-whiplash patients scored as low as the patients with closed head injury on most tests. CONCLUSIONS: The prevalence of malingering or cognitive underperformance in late post-whiplash patients is substantial, particularly in litigation contexts. It is not warranted to explain the mild cognitive disorders of whiplash patients in terms of brain damage, as some authors have done. The cognitive complaints of non-malingering post-whiplash patients are more likely a result of chronic pain, chronic fatigue, or depression.

Adult↗
PubMed1993

Treatment of complex I deficiency with riboflavin.

We have evaluated the effects of treatment with riboflavin in five patients with a mitochondrial myopathy, associated with a complex I (NADH dehydrogenase) deficiency. Two patients suffered from a clinically pure myopathy and the other patients presented with encephalomyopathic features. Treatment with riboflavin resulted in a clear clinical improvement in the two patients with the myopathic form of complex I deficiency. However, only one of the patients with the encephalomyopathic form improved during therapy. In three of the four patients in whom complex I activity in muscle tissue has been determined again during therapy, complex I activity appeared to be normalized. The clinical effects of treatment in this group of patients do not correlate well with normalization of complex I activity.

Adolescent↗
PubMed1992

Cognition in epilepsy: a multichannel event related potential (P300) study.

Auditory event-related potentials (AERP) were elicited in 68 epileptic patients and 30 age-matched controls. Epileptic patients had significantly prolonged N2 and P300 (P3) latencies compared with controls. Seven patients were above the range of 3 standard deviations from the control mean values. Amongst epileptics, patients with temporal lobe epilepsy had significantly prolonged P3 latencies compared to patients with idiopathic generalized epilepsy. Patients with abnormal EEGs had significantly prolonged P3 latencies compared to those with normal EEGs. Patients on anticonvulsant monotherapy had shorter P3 latencies, compared to patients taking a combination of two or more anticonvulsants. Patients on shorter duration of treatment had less prolonged P3 latencies compared to those on longer anticonvulsant treatment.

Adolescent↗
PubMed1991

Global field power measurement versus classical method in the determination of the latency of evoked potential components.

The Global Field Power measurement (GFPM) was proposed as a method for the determination of component latency in multichannel evoked potential (EP) recordings (Lehmann and Skrandies 1980). In contrast to the classical method (CM) of peak latency determination using only two or three electrodes, multichannel recordings deal with data from twenty or more recording electrodes. We compared the GFPM and CM in evoked potential recordings. Sixty five subjects volunteered for 3 different response tasks. In a P3 oddball paradigm targets consisted of 2000 Hz tonebursts, nontargets of 1000 Hz tonebursts. Flash and Pattern Visual Evoked Potentials (VEP) also were recorded. At peak GFPM latency we found steeper voltage gradients than at CM latency. Both N200 and P300 had a significantly different topography at latencies determined by GFPM than at latencies determined by CM. For VEP we did not find a significant difference between CM and GFPM. Our Data suggests that multichannel recording adds additional dimensions to EP measurements and that only GFPM leads to an unbiased data-reduction as it determinesone momentary map in time which has maximal field strength.

Adolescent↗
PubMed1990

Clinical applications of auditory event related potentials in neurology.

Auditory ERP (AERP) studies have been performed in 56 patients with central nervous system disturbances. Forty seven patients (90.5%), had AERP component abnormalities concerning mainly P300 topography alterations and secondarily P300 latency prolongation. It is concluded that P300 is a very useful tool in clinical neurology and that P300 topography or latency alterations are not specific of any cerebral disturbance but can be found in any disease whenever cognitive functions are impaired.

Acoustic Stimulation↗
PubMed1986

Pain and neuroma formation in Wallenberg's lateral medullary syndrome.

We report a patient with a Wallenberg's lateral medullary syndrome in which pain was a prominent feature. This led to substitution of the original and correct diagnosis by that of a thalamic syndrome for which a prefrontal leucotomy was performed. The patient died some years later from a myocardial infarction and autopsy was performed. In the dorsolateral part of the medulla oblongata a cavity was found in which aberrant nerve fibres with neuroma-like formations could be seen. These fibres coursed along blood vessels, and penetrated from the surface of the medulla oblongata. On the base of the clinico-pathological correlations, it is conjectured that destruction of the lateral reticular formation cannot be the sole cause of the severe pain.

Brain Neoplasms↗
PubMed1982

Butterfly vertebra.

A patient with a so-called 'butterfly vertebra' is presented. Radiography, including computed tomography, is shown. The embryology and pathogenesis of the vertebral column with respect to vertebral abnormalities are discussed, with special reference to butterfly vertebra. Finally, attention is paid to the clinical manifestations.

Adult↗