Atypical Facial Pain

Abstract

Atypical facial pain describes a heterogeneous group of pain syndromes that have in common the fact that the facial pain cannot be classified as trigeminal neuralgia. The pain is continuous but may vary in intensity. It is almost always unilateral and may be characterized as aching or cramping, rather than the shocklike neuritic pain typical of trigeminal neuralgia. Most patients suffering from atypical facial pain are female. The pain is felt in the distribution of the trigeminal nerve but invariably overlaps the divisions of the nerve. Headache often accompanies atypical facial pain and is clinically indistinguishable from tension-type headache. Stress is often the precipitating factor or an exacerbating factor in the development of atypical facial pain. Depression and sleep disturbance are also present in many patients. A history of facial trauma, infection, or tumor of the head or neck may be elicited in some patients with atypical facial pain, but in most cases, no precipitating event can be identified.

Keywords

atypical facial pain, temporomandibular joint dysfunction, dental malocclusion, depression, antidepressants, trigeminal neuralgia, bruxism, inflammatory arthritis

ICD-10 CODE G50.1

The Clinical Syndrome

Atypical facial pain (also known as atypical facial neuralgia) describes a heterogeneous group of pain syndromes that have in common the fact that the facial pain cannot be classified as trigeminal neuralgia. The pain is continuous but may vary in intensity. It is almost always unilateral and may be characterized as aching or cramping, rather than the shocklike neuritic pain typical of trigeminal neuralgia. Most patients suffering from atypical facial pain are female. The pain is felt in the distribution of the trigeminal nerve but invariably overlaps the divisions of the nerve ( Fig. 12.1 ).

Headache often accompanies atypical facial pain and is clinically indistinguishable from tension-type headache. Stress is often the precipitating factor or an exacerbating factor in the development of atypical facial pain. Depression and sleep disturbance are also present in many patients. A history of facial trauma, infection, or tumor of the head or neck may be elicited in some patients with atypical facial pain, but in most cases, no precipitating event can be identified.

Signs and Symptoms

Table 12.1 compares atypical facial pain with trigeminal neuralgia. Unlike trigeminal neuralgia, which is characterized by sudden paroxysms of neuritic shocklike pain, atypical facial pain is constant and has a dull, aching quality, but it may vary in intensity. The pain of trigeminal neuralgia is always within the distribution of one division of the trigeminal nerve, whereas atypical facial pain always overlaps these divisional boundaries. The trigger areas characteristic of trigeminal neuralgia are absent in patients suffering from atypical facial pain.

TABLE 12.1

Comparison of Trigeminal Neuralgia and Atypical Facial Pain

	Trigeminal Neuralgia	Atypical Facial Pain
Temporal pattern of pain	Sudden and intermittent	Constant
Character of pain	Shocklike and neuritic	Dull, cramping, aching
Pain-free intervals	Usual	Rare
Distribution of pain	One division of trigeminal nerve	Overlapping divisions of trigeminal nerve
Trigger areas	Present	Absent
Underlying psychopathology	Rare	Common