Comparative anatomy of the caudate nucleus in canids and felids: Associations with brain size, curvature, cross-sectional properties, and behavioral ecology.

The evolutionary history of canids and felids is marked by a deep time separation that has uniquely shaped their behavior and phenotype toward refined predatory abilities. The caudate nucleus is a subcortical brain structure associated with both motor control and cognitive, emotional, and executive functions. We used a combination of three-dimensional imaging, allometric scaling, and structural analyses to compare the size and shape characteristics of the caudate nucleus. The sample consisted of MRI scan data obtained from six canid species (Canis lupus lupus, Canis latrans, Chrysocyon brachyurus, Lycaon pictus, Vulpes vulpes, Vulpes zerda), two canid subspecies (Canis lupus familiaris, Canis lupus dingo), as well as three felids (Panthera tigris, Panthera uncia, Felis silvestris catus). Results revealed marked conservation in the scaling and shape attributes of the caudate nucleus across species, with only slight deviations. We hypothesize that observed differences in caudate nucleus size and structure for the domestic canids are reflective of enhanced cognitive and emotional pathways that possibly emerged during domestication.

A superficial dissection approach to the sphenopalatine (pterygopalatine) ganglion to emphasize osteopathic clinical relevance.

The sphenopalatine (pterygopalatine) ganglion (SPG) is the most superficial ganglia to manipulate from the oral cavity. It has parasympathetic and sensory fibers directly affecting the paranasal sinuses as well as the palatine, nasal, pharyngeal, and lacrimal glands. The SPG can be manipulated intraorally by students and physicians utilizing osteopathic manipulative treatment (OMT) to relieve congestion associated with sinusitis, allergies, headaches, and upper respiratory infections. Within osteopathic medical education programs, students have anecdotally had difficulty identifying this ganglion due to its deep anatomic location and lack of direct visualization. In this article, we discuss that cadaveric dissection with a superficial to deep approach to the SPG has the ability to allow medical students and physicians to better understand the three-dimensional location and osteopathic clinical relevance of this ganglion.

Supine counterstrain technique for rhomboid tender point.

Because poor posture is a common instigating factor in back, shoulder, and neck pain, the rhomboid muscles should be considered in a complete physical evaluation. Previous techniques for treating a rhomboid tender point have addressed only one of the two main actions of the muscle, specifically retraction of the scapula utilizing shoulder abduction. This modified supine counterstrain technique for the rhomboid tender point incorporates both scapular retraction as well as superior, medial rotation of the inferior border of the scapula without abduction, providing a comprehensive treatment to accommodate patients with shoulder movement restrictions. This article discusses indications, contraindications, treatment, and a list of problem-solving strategies for the rhomboid tender point.

Counterstrain technique for anterior and middle scalene tender point.

When a patient presents with head, neck, or respiratory concerns, the scalene muscles are not commonly considered. However, somatic dysfunctions of the anterior/middle scalenes (AMS) can be contributing to or causing these medical concerns. Although tender points within the scalene muscles have been documented within the muscle belly, they have not been documented at the insertion site. This article details how to diagnose and treat an AMS tender point with an efficient technique that requires minimal exertion and maximal comfort for both the physician and patient at a new tender point location. This article also discusses the importance of this tender point and provides a list of additional somatic dysfunctions that may be used to problem-solve a scalene tender point that fails to correct.

Anatomy-based approach to the thyroid examination.

In this article, the authors will discuss a modified anatomy-based neck and thyroid examination that allows for a more comprehensive evaluation. It is the opinion of the authors that an organ and its function are best evaluated utilizing the following steps: anatomy-based inspection and palpation, imaging, and blood tests. Approximately half of the lateral part of the thyroid is deep to the sternocleidomastoid (SCM) and sternothyroid muscles, which makes it rather difficult to palpate the entire gland utilizing prior physical examination techniques. The goal of this modified anatomy-based thyroid examination is to minimize the number of structures between the physician's fingers and the patient's thyroid by utilizing neck flexion, side bending, and rotation. If one approaches the thyroid from behind the patient, nodules can be missed due to the muscles and transverse processes overlaying them. The incidence of thyroid cancer in the United States is drastically increasing, which demonstrates the importance of a more thorough thyroid palpation. Our anatomy-based approach may allow for earlier detection and therefore earlier treatment.

The Effect of Huntington's Disease on the Basal Nuclei: A Review.

Huntington's disease is an autosomal dominant trinucleotide repeat disorder that causes the progressive degeneration of the basal nuclei. This degeneration leads to clinical symptoms affecting voluntary movement, cognitive impairment, and psychiatric disorders. The patient affected by this disease demonstrates anticipation, meaning that even though there is normal embryological development, the signs and symptoms appear at an earlier age as the gene is continually passed throughout subsequent generations. The degeneration occurs due to the accumulation of the protein Huntingtin that destroys the medium spiny neurons located in the caudate and putamen, collectively termed the striatum. Four pathways converge onto the striatum known as the "input" center. These consist of the motor loop, oculomotor loop, association loop, and limbic loop. In each of these loops, the striatum maintains an inhibitory gamma-aminobutyric acid (GABA)-ergic function. The imbalance of the inhibitory versus excitatory input directly relates to the symptoms seen in Huntington's disease such as the inability to control voluntary movements termed chorea, the inability to control voluntary saccadic ocular movements, the cognitive inability to plan and determine the direction of movement, and the inability to control the emotional and motivational aspects of the movement. There is currently no cure for Huntington's disease but there is a symptomatic treatment for the chorea and psychiatric conditions. Further research is being done to determine the pathophysiology behind the Hungtintin protein to allow for a targeted treatment regimen while also looking into reliable biomarkers for the progression of Huntington's disease.