Division of neuromuscular compartments and localization of the center of the highest region of muscle spindles abundance in deep cervical muscles based on Sihler's staining.

Purpose: The overall distribution pattern of intramuscular nerves and the regions with the highest spindle abundance in deep cervical muscles have not been revealed. This study aimed to reveal neuromuscular compartmentalization and localize the body surface position and depth of the center of the region of highest muscle spindle abundance (CRHMSA) in the deep cervical muscles. Methods: This study included 36 adult cadavers (57.7 ± 11.5 years). The curved line joining the lowest point of the jugular notch and chin tip was designated as the longitudinal reference line (line L), and the curved line connecting the lowest point of the jugular notch and acromion was designated as the horizontal reference line (line H). Modified Sihler's staining, hematoxylin-eosin staining and computed tomography scanning were employed to determine the projection points (P) of the CRHMSAs on the anterior surfaces of the neck. The positions (PH and PL) of point P projected onto the H and L lines, and the depth of each CRHMSA, and puncture angle were determined using the Syngo system. Results: The scalenus posterior and longus capitis muscles were divided into two neuromuscular compartments, while the scalenus anterior and longus colli muscles were divided into three neuromuscular compartments. The scalenus medius muscle can be divided into five neuromuscular compartments. The PH of the CRHMSA of the scalenus muscles (anterior, medius, and posterior), and longus capitis and longus colli muscles, were located at 36.27, 39.18, 47.31, 35.67, and 42.71% of the H line, respectively. The PL positions were at 26.53, 32.65, 32.73, 68.32, and 51.15% of the L line, respectively. The depths of the CRHMSAs were 2.47 cm, 2.96 cm, 2.99 cm, 3.93 cm, and 3.17 cm, respectively, and the puncture angles were 87.13°, 85.92°, 88.21°, 58.08°, and 77.75°, respectively. Conclusion: Present research suggests that the deep cervical muscles can be divided into neuromuscular compartments; we recommend the locations of these CRHMSA as the optimal target for administering botulinum toxin A injections to treat deep cervical muscle dystonia.

Relationship between echogenicity of deep cervical muscles and pain laterality in subjects suffering from cervicogenic headache.

OBJECTIVE: This study investigated the deep upper cervical muscles echogenicity in cervicogenic headache (CGH) patients. METHODS: The echogenicity of longus capitis (LCAP), rectus capitis posterior major (RCPM), and obliquus capitis superior (OCS) muscles was measured by ultrasonography and analyzed by Image J software in 17 CGH patients matched with 17 healthy subjects. RESULTS: The echogenicity of all muscles in the CGH group was higher than that in healthy subjects. The echogenicity of the LCAP muscle on the right side was significantly different between the CGH and healthy subjects (p< 0.05), but there was no difference in the echogenicity of RCPM and OCS muscles between the groups (p> 0.05). Additionally, the echogenicity differences did not match with the pain side in CGH patients (p> 0.05). CONCLUSION: Only the deep anterior muscle (LCAP) echogenicity affected by CGH and fatty infiltration occurred in this muscle. Hence, anterior muscle dysfunction is important in CGH diagnosis and treatment.

Neck and Occipital Pain Caused by Deep Cervical Intramuscular Lipoma: A Surgical Case.

A lipoma is a slow-growing, benign tumor and is usually asymptomatic; hence, surgical intervention can often be avoided in patients with these tumors in the cervical and cranial area. Lipomas arise most commonly in the subcutaneous fat, but occasionally in muscle tissue. Intramuscular lipomas in the cervico-cranial area have rarely been reported. We describe here a patient with a large intramuscular lipoma in the deep cervical tissue. The patient experienced troublesome pain in the neck and occipital area, and surgical treatment was therefore suggested. Particularly in the cervical area, intramuscular lipomas sometimes invade the surrounding muscles and tissue layers and develop into an irregular mass, despite being benign. In addition, the cervical area has one of the most complex muscle structures. Nevertheless, surgical management of intramuscular lipoma in the cervical and cranial area is sometimes indicated, for example, in patients with clinical symptoms or masses with a tendency to grow large.