Deep Neck Space Infections - Anatomy

The prevertebral fascia is located behind or posterior to the danger space. The danger space is a potential space in the neck that lies between the prevertebral fascia and the alar fascia. Therefore, the correct answer is posterior.

The alar fascia is located in front of or anterior to the danger space.

Infection of the peritonsillar space can extend into the parapharyngeal space. The parapharyngeal space is located behind the pharynx and extends from the base of the skull to the level of the hyoid bone. It is adjacent to the peritonsillar space and can serve as a pathway for the spread of infection. This can lead to complications such as deep neck abscesses or cellulitis.

The peritonsillar space is a space located around the tonsils in the throat. It is a localized space and does not involve the entire length of the neck. The retropharyngeal space, danger space, and prevertebral space are all spaces that extend along the entire length of the neck. Therefore, the peritonsillar space is the only option that does not involve the entire length of the neck.

The space that is not limited to above the hyoid bone is the visceral vascular space. The hyoid bone is located in the neck, and the visceral vascular space extends below it. The other options, such as the submandibular space, parotid space, and masticator space, may be located above or around the hyoid bone. However, the visceral vascular space extends beyond this boundary.

The distribution of bacteria involved also reflects the changing pattern of origin, and odontogenic sources are thought to be the most common origin of deep space infections in the adult population. Salivary gland infections, penetrating trauma, trauma from surgical instrumentation, retained foreign bodies, and spread from superficial infections account for a smaller percentage of deep neck space infections, and in many cases (20%), the source of infection may never be ascertained.

The middle layer of the deep cervical fascia contains the esophagus. The deep cervical fascia is a layer of connective tissue that surrounds the neck and divides it into different compartments. The middle layer, also known as the pretracheal fascia, is located anteriorly to the trachea and esophagus. It provides support and protection to these structures.

It invests or surrounds (hence the anatomic term investing layer) two muscles, viz. the sternocleidomastoid and trapezius, and two glands viz. the parotid and submandibular glands

The deep layer of the deep cervical fascia contains the phrenic nerve. This layer is located deep within the neck and provides support and protection to various structures, including the phrenic nerve. The phrenic nerve is responsible for innervating the diaphragm, which is a crucial muscle involved in the process of breathing. Therefore, it makes sense for the phrenic nerve to be located within the deep layer of the deep cervical fascia, which is closer to the structures it innervates.

The deep layer of the deep cervical fascia contains the danger space. This layer is located deep to the superficial and middle layers and is responsible for separating the structures in the neck. The danger space is a potential space located posterior to the visceral compartment of the neck, extending from the base of the skull to the diaphragm. It is called the danger space because infections or tumors in this area can spread easily to other regions of the body, making it a significant anatomical consideration.

The fascial layer that was dubbed the ‘Lincoln highway’ is the Carotid sheath.

The middle layer of the deep cervical fascia contains the strap muscles.

Superiorly, it also splits around the anterior belly of the digastric muscle, while inferiorly in the region of the sternal notch, between the sternal heads of the sternocleidomastoid muscles it splits to form the suprasternal space of Burns, which sometimes contains a lymph node, and an anastomotic vessel between the two anterior jugular veins

In the superficial fascia are flat sheets of muscle called the panniculus carnosus, which help certain animals (e.g., domestic quadrupeds) to move their skin. An essential feature of the panniculus carnosus is that one end of the muscle fiber is attached to the skin while the other is attached to the deep fascia or bone. Infections that are within this superficial layer, such as erysipelas, are referred to as superficial infections and are usually managed by antibiotics and incision and drainage.

The deep fascia, referred to by anatomists as the investing layer of deep fascia (in the neck it is called the investing layer of deep cervical fascia), on the other hand comprises fibrous tissue, which is largely devoid of fat and which varies in thickness. While the deep fascia is attached to periosteum and bone in a few places, in general, muscles and organs are free to glide beneath the deep fascia as they contract and relax.

The middle layer of the deep cervical fascia contains the ligament of berry.

The middle layer of the deep cervical fascia blends with the fibrous pericardium. This layer provides support and protection to the structures in the neck, including the blood vessels, nerves, and lymph nodes. It also helps to compartmentalize these structures and prevent the spread of infections. The blending of the middle layer with the fibrous pericardium ensures a strong connection between the fascia and the pericardium, further enhancing the stability and integrity of the neck structures.

This occurs as the medial pterygoid muscle, which lies in proximity and undergoes spasm from inflammation. Also there is a tendency for patients to hold their heads still with the neck slightly flexed and head rotated to the opposite side in an attempt to decrease the tension in the space. There is often drooling as the patient suffers dysphagia.