Diagnostic test for catatonia, the lorazepam challenge test

Diagnostic test for catatonia, the lorazepam challenge test
Benzodiazepines are the mainstay of the treatment of catatonia and are also helpful as a diagnostic probe.

1. A positive Lorazepam Challenge Test validates the diagnosis of catatonia.
2. After we examine the patient for signs of catatonia, 1 or 2 mg of lorazepam is administered intravenously.
3. After 5 minutes, the patient is re-examined. If there has been no change, a second dose is given, and the patient is again reassessed (46, 78).
4. A positive response is a marked reduction (e.g., at least 50%) of catatonic signs and symptoms, measured with a standardized rating scale.
5. Favourable responses usually occur within 10 min (46). If lorazepam is given intramuscularly or per os, the interval for the second dose should be longer: 15′ and 30′, respectively. Many clinicians will share the experience that a “lorazepam test” not only confirms the diagnosis of catatonia but that it also makes the underlying psychopathology apparent “by permitting mute patients to speak” (79).
6. Analogous to the lorazepam test, a Zolpidem Challenge Test was proposed (80, 81). In this test, 10 mg of zolpidem is administered per os, and after 30 minutes, we examine the patient.
7. A positive response is a reduction of at least 50% of the BFCRS score. After a positive response, we can start treatment.