Catatonia Workup

Updated: Sep 18, 2023
  • Author: James Robert Brasic, MD, MPH, MS, MA; Chief Editor: Selim R Benbadis, MD  more...
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Approach Considerations

On the grounds that treatment of the underlying disorder relieves the catatonia, Lahutte et al recommended prompt diagnosis and therapy of the comorbid disorders to prevent morbidity and mortality. [83] This process includes appropriate use of laboratory tests, imaging modalities, and electroencephalography (EEG). EEG is performed to rule out underlying causes. [84] While an EEG often reveals focal abnormalities or generalized slowing, an EEG may be normal in catatonia.

Lorazepam challenge can also help the diagnosis of catatonia. Patients who respond to the first or two doses of IV lorazepam (1 to 2 mg) are likely to have catatonia. Partial or temporary relief of symptoms and signs of catatonia after 5 to 10 minutes of injection is consistent with catatonia. [85, 1]

An effort should be made to assess the degree of catatonia present. Of the several scales that have been developed to measure catatonia, the Bush-Francis Catatonia Rating Scale (BFCRF) is favored, owing to its demonstrated reliability and validity in clinical settings. [86, 87]


Laboratory Studies

A complete blood count (CBC), measurement of electrolyte concentrations, and chemical analyses of blood are appropriate. In particular, hyponatremia and other metabolic abnormalities must be ruled out.

Fibrin D-dimer levels must be obtained to rule out early coagulation activation. [63] Patients with catatonia typically have fibrin D-dimer levels higher than 500 ng/mL. [63] Prompt identification and treatment of pulmonary embolism in people with catatonia are crucial for minimizing morbidity and mortality. [88]

To rule out neuroleptic malignant syndrome (NMS), immediate evaluation of the serum creatine kinase level, white blood cell (WBC) counts, and liver function test results is warranted. Measurement of serum ceruloplasmin is needed to rule out Wilson disease. In addition, encephalitis must be ruled out.


Magnetic Resonance Imaging and Computed Tomography

Imaging of the head by means of magnetic resonance imaging (MRI) or computed tomography (CT) is indicated to rule out treatable mass lesions. If no evidence of increased intracranial pressure is noted on imaging, lumbar puncture is appropriate to rule out encephalitis and other infections, hemorrhages, and tumors.

People with catatonia may exhibit increased ventricle-to-brain ratios on CT scans. However, CT cannot be used to establish the diagnosis of catatonia. The main value of CT in patients with catatonia is to rule out other treatable disorders.

Single-photon emission CT (SPECT) has demonstrated increased cerebral blood flow in the parietal, temporal, and occipital regions of some patients with catatonia secondary to mood disorders after treatment with electroconvulsive treatment (ECT). However, SPECT cannot be used to establish the diagnosis of catatonia. The main value of SPECT in patients with catatonia, like that of CT, is to rule out other treatable disorders.


Positron Emission Tomography

Positron emission tomography (PET) with fluorodeoxyglucose (FDG) reveals bitemporal hypometabolism in catatonia. Patients with various vegetative states have demonstrated decrements in regional cerebral blood flow in the prefrontal and the parietotemporal association areas. However, PET cannot be used to establish the diagnosis of catatonia. The main value of PET in patients with catatonia is to rule out other treatable disorders. [10, 11]



EEG is indicated to rule out a seizure disorder. Nonconvulsive status epilepticus can readily be identified on EEG. Obtaining a portable EEG in the emergency department (ED) may quickly confirm the presence of nonconvulsive status epilepticus.

EEG changes in catatonia typically include focal abnormalities or generalized slowing. [4] However, a normal EEG may occur in a patients with the excited state of catatonia due to anti-NMDA receptor encephalitis. [4] Therefore, a normal EEG in a patient with catatonia does not rule out the presence of cerebral pathology.

During the psychotic episodes of periodic catatonia, alpha rhythm is characterized by an increase in frequency and a decrease in amplitude. In a patient with periodic catatonia, increased urinary excretion of 4-hydroxy-3-methoxy-mandelic acid (VMA) and of normetadrenaline correlated with increased frequences of alpha rhythm. [89, 90]


Other Tests

Transcranial magnetic stimulation (TMS) is a procedure under investigation for patients with catatonia.