Assessing the severity of tardive dyskinesia: A step-by-step guide on how to use the Abnormal Involuntary Movement Scale (AIMS)

Tardive dyskinesia (TD) is an involuntary movement disorder caused by exposure to dopamine receptor-blocking antagonists, most commonly antipsychotic drugs.^1,2 While TD is chronic, physical symptoms may fluctuate in severity over time.³ Severity of TD does not always correlate with impact, and a patient's productivity, daily activities, and social life may be impacted, even when symptoms are mild.^4,5 TD may also have a negative impact on a patient’s underlying psychiatric health condition and can lead to additional psychological issues.^5,6 It is therefore essential that at-risk patients are regularly assessed, and symptoms monitored.⁵

The Abnormal Involuntary Movement Scale (AIMS) is an examination tool used to measure the severity and degree of impairment associated with TD.⁷

How is AIMS scored?

The AIMS is a twelve-item, clinician-rated assessment tool.^7,8 The first seven items of AIMS assess the severity of involuntary movements in different areas of the body.⁷ The remaining four address overall TD severity, patient impairment and awareness, and dental issues.⁷ Most items are scored from 0 to 4, where 0 denotes 'not present' and 4 denotes 'severe' (i.e. abnormal movements occur almost continuously and/or are of extreme intensity).⁷ The questions about dental status require 'yes' or 'no' answers.^7,8 The total AIMS score is the sum of the first seven items, and can range from 0 to 28.^7,8

Facial and oral movements

The most distinctive symptoms of TD are involuntary movements of the mouth or face.^3,9 These are considered in the first four AIMS items. The patient is asked to tap their fingers or perform another activating movement to allow the physician to assess movements in:^7,8                                                                       • Muscles of the forehead, eyebrows, periorbital area, and cheeks (i.e. frowning, blinking, smiling,  grimacing)                                                                                                                                                                   • Lips and perioral regions (i.e. puckering, pouting, smacking)                                                                   • Jaw (i.e. biting, clenching, chewing, mouth opening, lateral movement)                                             During the tongue assessment, patients are asked to open their mouth and protrude their tongue while repeating the same activating movement.^7,8  

Movements of the upper and lower extremities

In some patients, involuntary movements caused by TD can affect the limbs.³ AIMS items five and six are designed to assess the upper (arms, wrists, hands, fingers) and lower (legs, knees, ankles, toes) extremities.^7,8 The physician should observe the patient when walking, sitting (with hands over knees or hanging unsupported), and standing (with arms extended in front and palms down).^7,8 Rapid, purposeless, irregular, or spontaneous movement of the extremities (i.e. choreatic) should be included in the assessment.^7,8 Athetoid movement (i.e. slow, irregular, complex, serpentine) should also be assessed, while tremor movements (i.e. repetitive, regular, rhythmic) should be disregarded.^7,8

Trunk movements

Item seven of AIMS records any involuntary movement of the trunk (i.e. neck, shoulder, hips).^7,8 While the patient is standing with their arms extended and palms down, the physician should identify any rocking, twisting, or squirming of the truncal region, as well as any pelvic gyrations.^7,8 This assessment should also be carried out when the patient is walking.^7,8 

Global judgements

AIMS can also be used to assess the impact of living with TD through items eight to ten.^7,8 Item eight provides an overall assessment of the severity of abnormal movements (taking the highest single score from items one to seven), item nine records the degree of incapacitation the patient experiences from TD, and item ten assesses the patient’s awareness of involuntary movements.^7,8 Assessing the impairment related to the abnormal movements can improve healthcare professional and patient conversations and eventually reduce the impact that TD has on the patient.^10,11

Dental status

In some patients, TD manifests as abnormal oral movements, such as cracking or grinding of teeth.³ Item eleven of AIMS captures whether the patient has current dental issues, and item twelve identifies whether the patient usually wears dentures.^7,8 

Download this educational infographic to learn more about how AIMS can be used to assess TD, including video examples of the various stages of AIMS.