Biomedical subjects

N Becser

Publications and source records attributed to N Becser.

5 recordsLinked to original sources

PubMed1998

Extracranial nerves in the posterior part of the head. Anatomic variations and their possible clinical significance.

STUDY DESIGN: An anatomic study of the peripheral nerves innervating the occipital region. OBJECTIVES: To study the topography of the extracranial occipital nerves, to define optimal locations for anesthetic nerve blockades, to provide guidelines to use with the suboccipital surgical approach, and to search for structures with putative pathogenetic implications in cases of unilateral headache. SUMMARY OF BACKGROUND DATA: There is little consensus in the literature concerning the sensory innervation of the scalp. Previous clinical and morphologic studies have not proven the existence of an entrapment mechanism in cases of unilateral head pain. Specific sites for anesthetic blockades have been defined only partly with reference to topographic landmarks. METHODS: The topography of the greater occipital (n = 20), the minor occipital (n = 19), and the greater auricular nerves (n = 17) was studied by dissection of 10 embalmed cadavers. Measurements of internerve distances and distances to defined landmarks were supplemented by drawings and photographs. RESULTS: A great variability in nerve topography was seen interindividually and intraindividually. The greater occipital nerve ascended between 5 mm and 28 mm from the midline along the intermastoid line. The minor occipital nerve was found between 32 mm and 90 mm from the midline along the same landmark. In most cases, both the greater occipital nerve and the minor occipital nerve pierced the aponeurosis after branching. Thirteen greater occipital nerves and eight minor occipital nerves also were embedded in this tissue. Twelve of the 20 greater occipital nerves formed a rich network around the occipital artery. However, anatomic structures with an imminent risk of causing entrapment were not observed. CONCLUSION: The results of this study suggest that optimal locations for blockade techniques should be reconsidered. The acquired knowledge concerning greater auricular and minor occipital nerves behind the sternocleidomastoid muscle may aid in preventing intraoperative injuries.

Female↗

PubMed1998

Reliability of cephalic thermal thresholds in healthy subjects.

Reproducibility and normal variation of cephalic warm and cold detection thresholds were investigated in three healthy subject groups. The face, the mastoid process, and the hands were studied. No significant intra-observer test-retest difference (n = 20) was found. Good reliability (intra-class correlation coefficient [ICC] > 0.4) was found for 13 of 14 measurements. A small significant inter-observer difference (n = 20) was found for cold thresholds. Good reliability (ICC > 0.4) was observed for both cold and warm thresholds in most of the test locations (6 of 8). In general, the largest variability was found in the mastoid and frontal lateral regions. Thermal thresholds varied with investigation site in 56 controls (ANOVA, p < 0.0005). No significant gender differences were found for cephalic warm and cold thresholds. Most cold thresholds (4 of 5) but also some warm thresholds (2 of 5) increased with age at the cephalic sites. Our results reveal the frontal medial, the maxillar medial, and lateral regions as the most reliable cephalic test locations. The mastoid region may also be useful for investigating the upper cervical small-fiber function.

Adolescent↗

PubMed1998

Thermal sensitivity in unilateral headaches.

Thermal thresholds were measured in the face (first and second trigeminal area), over the mastoid process (C2-3 area), and in the hands in patients with migraine (n=17), cluster headache (n=22), and cervicogenic headache (n=20). Significant symptomatic versus nonsymptomatic side differences were generally not found for any headache group. Cluster headache patients had significantly higher warm thresholds than controls (n=24) for most of the cephalic points. Cervicogenic headache patients had significantly higher warm and cold thresholds than controls (n=56) at several cephalic and noncephalic points. Warm thresholds over the mastoid process on the symptomatic side were higher in cervicogenic headache patients compared to the other groups. In migraine patients, thermal thresholds were similar to those in controls. Thus, we found no evidence of focal or unilateral peripheral somatic nerve dysfunction involving C or A-delta fibers in any of the studied headache groups, although a C2-3 root dysfunction in cervicogenic headache could not be excluded. A bilateral central sensory dysfunction in cluster headache and cervicogenic headache may be hypothesized but a generalized peripheral dysfunction can also explain our results.

Adult↗

PubMed1998

Neurophysiological and anatomical variability of the greater auricular nerve.

OBJECTIVE: To study the normal variation in greater auricular nerve (GAN) conduction and anatomical course. MATERIALS AND METHODS: GAN nerve conduction was studied in 77 healthy adults while 17 GANs were dissected in 10 cadavers. RESULTS: The largest sensory nerve action potentials (SNAP) were recorded when the stimulator was placed 6 or 7 cm from the external acoustic meatus (EAM). Amplitude decreased significantly with age (P = 0.001). The dissected GANs entered the subcutaneous layer between 55 and 105 mm (median 68 mm) from EAM. The postauricular branch was found in 13 of 17 cases. CONCLUSION: A large variation was observed both anatomically and by way of electrical stimulation. SNAP variation does probably reflect the anatomical variation in GAN course, branching, and terminal distribution. The best sites for stimulation were found 6 and 7 cm from EAM at the posterior sternocleiodomastoid border. The maximal amplitude, right:left amplitude ratio, and distal latency may be useful variables in GAN conduction studies.

Action Potentials↗

PubMed1995

SUNCT syndrome: a Hungarian case.

A Hungarian patient with short-lasting, unilateral, neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) is presented in this paper. This male patient was first diagnosed as having first division trigeminal neuralgia. The location and duration of the attacks and the prominent accompanying autonomic features on the symptomatic side, such as conjunctival injection, lacrimation, nasal stuffiness, and the inefficacy of drugs, led to a reconsideration of the diagnosis. The pain paroxysms occurred frequently during a 3- to 4-month period, followed by a longer remission phase. Mechanical precipitating maneuvers were observed during bouts of pain. The clinical picture is reminiscent of the SUNCT syndrome, first described by Sjaastad et al in 1978. SUNCT and trigeminal neuralgia are in many ways similar, although, some decisive differences have also been noted. Further observations are needed to distinguish the two disorders and to clarify this syndrome as a new headache type or as a trigeminal neuralgia variant.

Aged↗