Phenotypes and Genotypes in Postherpetic Neuralgia Drug Therapy: A Narrative Mini-review.

Neuropathic pain is a debilitating symptom reported by patients presenting with postherpetic neuralgia (PHN). Efforts to alleviate this pain have been projected to lie in individualization of pharmacological treatment through pain phenotyping and subsequent investigations into the genetic basis of PHN therapy. Understanding the various mechanisms related to these phenotypes can aid in improvement of available treatment options and discovery of new ones. Knowledge and application of genetic variations in PHN, structural proteins, and genes can aid in ascertaining risk, susceptibility to, severity of, and protection from PHN. This review summarizes the most recent information that has been published on phenotypes and genotypes with possible clinical applications and directions for future research.

Anatomical Variations in the Origin of the Lumbar Artery: A Cadaveric Study Augmented by CT Findings.

BACKGROUND: Anatomical variations of lumbar arteries predispose them to iatrogenic injury during endovascular intervention or surgery. Due to limited morphological data on lumbar arteries in our setting, we aimed to determine their variant anatomy among Kenyans. METHODS: We performed the study on 90 cadaveric specimens and 120 computed tomography (CT) scans. Cadavers were dissected to expose the aorta and the lumbar arteries emerging from them. The number, origins, location relative to the vertebral bodies, and relations to aortic bifurcation were determined in cadavers and CT scans. Data were analyzed using SPSS (version 21.0). RESULTS: On average, 3 (3/90 [3.3%]), 4 (63/90 [70%]) or 5 (24/90 [26.7%]) pairs of lumbar arteries were observed among the cadaveric specimens, whereas 4 (100/120 [83.3%]) or 5 (20/120 [16.7%]) pairs were observed in CTs. Differences in the number of pairs observed in the cadaveric versus CT study were not statistically significant (P = .542). There were no sex differences in the number of lumbar artery pairs observed in CT scans (P = .178). The first 3 lumbar artery pairs had a single-origin, whereas the fourth lumbar artery had a common-stem origin. The first, second, and third lumbar arteries mostly originated at the upper third of their respective vertebral bodies. The fourth lumbar artery predominantly originated at the lower third. CONCLUSION: Our study's findings show unique variation in the lumbar arteries' relation to the vertebral bodies and the distances between artery pairs. LEVEL OF EVIDENCE: IV (cross-sectional study). CLINICAL RELEVANCE: Variations in the anatomy of the lumbar arteries should be taken into consideration, especially in surgical or interventional procedures to avoid inadvertent injury of the vessels.

Valve distribution of the popliteal vein: A structural basis for deep venous thrombosis?

OBJECTIVE: To describe the relationship between number and distribution of valves. METHODS: Sixty-six popliteal vein specimens were used for the study after routine dissection at the Department of Human Anatomy, University of Nairobi. The extents of the popliteal vein were identified at the adductor hiatus and soleal arch, cut at these points and then longitudinally sliced open. The number and distribution of valves were then recorded. Data were presented using photomacrographs and tables. RESULTS: The median number of valves was 1 (mean 0.8; range 0-2), with the lower part of the popliteal vein as the most consistent valve position. Most striking was the valve absence noted in 27 (41%) of the veins. CONCLUSION: These findings suggest that a significant proportion of popliteal veins do not have valves thus providing a credible structural link that may predispose the popliteal vein to deep venous thrombosis in the study population.

Morphometric Dimensions of the Calcaneus.

Calcaneal morphometric dimensions influence surgical treatment plans after injury. These dimensions display population heterogeneity, and there is a paucity of data in the setting of our hospital in Kenya. Further, estimation of calcaneal dimensions during reconstruction in comminuted fractures can be difficult. This cross-sectional study therefore aims to determine equations for estimation of these dimensions as well as provide local data. Sixty-four bilateral calcanei of adult indigenous Kenyans were obtained from the National Museum of Kenya and measured for maximum anteroposterior length, maximum height, cuboidal facet height, body height, and load arm length. The data were coded into SPSS software, and means were calculated. Paired t tests, independent t tests, and Pearson correlation tests were done, and linear regression model equations were developed. Data are presented using tables. In millimeters, the mean right and left values, respectively, were as follows: maximum anteroposterior length, 36.1063 and 35.3047; maximum height, 68.958 and 68.266; cuboidal facet height, 27.815 and 27.841; body height, 47.94 and 48.98; and load arm length, 18.83 and 17.93. Paired and independent t tests did not reveal statistically significant difference between the variables based on side or sex. Pearson correlational tests between the maximum length on each side and other variables revealed strong positive correlations, apart from the maximum width and load arm length on both sides. All correlational R2 values were statistically significant, apart from that of the maximum width bilaterally. The calcaneus in our setting also showed markedly reduced values compared with other populations. These findings, and the proposed equations we developed, may be considered in local calcaneal reconstruction.

Variations in the attachments of the medial meniscal anterior horn: a descriptive cadaveric study.

PURPOSE: Meniscal tears are common in Kenya, with prevalence rates ranging from 45 to 78% of intracapsular knee pathology. Diagnosis of these injuries relies on the use of both clinical signs and symptoms as well as radiological investigations. In a few instances, radiological detection could be difficult, partly because of variant attachment patterns of the medial meniscal anterior horn. Some of these unusual attachments of the anterior horn of the medial meniscus could even be mistaken for meniscal tears. There is also evidence that these variations differ from population to population. This study, therefore, aimed to determine the variant bony and ligamentous attachments of the medial meniscal anterior horn in a sample Kenyan population. METHODS: The study was conducted at the Department of Human Anatomy, University of Nairobi. Thirty-one male and female unpaired medial menisci were obtained from cadaveric specimen. The bony and ligamentous attachments were identified and recorded and photomacrographs taken. RESULTS: The bony attachments different from the classical textbook attachment accounted for 54.8% of the medial meniscal anterior horns. The anterior intermeniscal ligament was present in 62.3% while 16.2% showed attachment to the anterior cruciate ligament. Twenty-nine percent (29%) of the medial menisci studied did not have any ligamentous attachments. CONCLUSIONS: The bony and ligamentous attachments of the medial meniscal anterior horn are highly variable presenting unique diagnostic and therapeutic challenges. A new classification of ligamentous attachments is thus proposed.