If the observed face is that of a person known to the patient, they experience that face as the face of an impostor (Capgras delusion). If the patient sees their own face, they might perceive no association between the face and their own sense of self—which results in the patient believing that they do not exist (Cotards syndrome). Cotards syndrome is usually encountered in people with psychosis, as in schizophrenia. It is also found in clinical depression, derealization, brain tumor, and migraine headaches. The medical literature indicate that the occurrence of Cotards delusion is associated with lesions in the parietal lobe. As such, the Cotards delusion patient presents a greater incidence of brain atrophy—especially of the median frontal lobe—than do people in control groups.Cotards delusion also has resulted from a patients adverse physiological response to a drug (e.g., acyclovir) and to its prodrug precursor (e.g., valaciclovir). The occurrence of Cotards delusion symptoms was associated with a high serum-concentration of 9-carboxymethoxymethylguanine (CMMG), the principal metabolite of acyclovir.As such, the patient with weak kidneys (impaired renal function) continued risking the occurrence of delusional symptoms despite the reduction of the dose of acyclovir. Hemodialysis resolved the patients delusions (of negating the self) within hours of treatment, which suggests that the occurrence of Cotards delusion symptoms might not always be cause for psychiatric hospitalization of the patient. Treatment
Pharmacological treatments, both mono-therapeutic and multi-therapeutic, using antidepressants, antipsychotics, and mood stabilizers have been successful.
Cotards delusion, also known as walking corpse syndrome or Cotards syndrome, is a rare mental disorder in which the affected person holds the delusional belief that they are dead, do not exist, are putrefying, or have lost their blood or internal organs. Statistical analysis of a hundred-patient cohort indicated that denial of self-existence is present in 45% of the cases of Cotards syndrome; the other 55% of the patients presented with delusions of immortality.In 1880, the neurologist Jules Cotard described the condition as le délire des négations ("the delirium of negation"), a psychiatric syndrome of varied severity. A mild case is characterized by despair and self-loathing, while a severe case is characterized by intense delusions of negation, and chronic psychiatric depression.The case of "Mademoiselle X" describes a woman who denied the existence of parts of her body (somatoparaphrenia) and of her need to eat. She claimed that she was condemned to eternal damnation, and therefore could not die a natural death. In the course of experiencing "the delirium of negation", Mademoiselle X died of starvation.Cotards delusion is not mentioned in either the Diagnostic and Statistical Manual of Mental Disorders (DSM) or the 10th edition of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) of the World Health Organization. Signs and symptoms
Delusions of negation are the central symptom in Cotards syndrome. The patient usually denies their own existence, the existence of a certain body part, or the existence of a portion of their body.