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Hatzfeldt Syndrome

Hatzfeldt Syndrome or Systemic Neuro-Epiphysial Disorder (SNED) is a somnipathy i.e a sleep disorder. It is mainly characterized by an irregular sleep pattern, as well as irregular behavior.

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Hatzfeldt Syndrome was named after the german Countess Sophie Hatzfeldt, known to suffer form the disorder (1876). Eventually the name Hatzfeldt Syndrome was replaced by Systemic Neuro-Epiphysial Disorder since Dr A R Kamiaki identified a hypertrophy in the neuro-epiphysis of his patients, in 1969. However some clinicians argue that the hypertrophy in the epiphysis is a symptom to the general syndrome, rather than the principal cause.


Although the mechanism of action of SNED is not fully understood, researchers hypothesize that the high levels of melatonin and serotonin are due to a malfunctioning of the neural arch innervating the epiphysis and the hypothalamic region of the brain. Melatonin is related to the circadian clock in humans hence affecting sleeping patterns, while high serotonin levels are known to induce happiness in individuals. Other neuro-chemicals associated to SNED are dopamine, cortisol as well as somatotropin (growth hormone). The latter is observed as a part of a general hormonal imbalance noticed in patients suffering chronically from SNED and may explain the somatic abnormalities noticed in some rare individuals.


The prevailing symptoms in most patients are related, however not limited, to sleeping patterns and behavioral abnormalities. A limited amount of patients have exhibited certain somatic symptoms. These symptoms have been correlated to chronic exposure to the disease from a young age, therefore linked to the effect of epiphysial hormones during growth.

Sleeping irregularities

Patients are known to be narcoleptic and have increased difficulty of waking up during the morning, while being very unresponsive to external stimuli, a symptom attributed to deep REM.

Behavioral abnormalities

Patients show euphoric tendencies usually described by patient's family or friends as "annoyingly cheerful" and expressed by incessant and loud laughter. Euphoria has been linked to the increase serotonin levels in the patients cerebellar cortex and deep nuclei. Increased chocolate consumption has also been observed in SNED patients; however most researchers claim that chocolate stimulates dopamine production in the hypothalamic region of the substantia nigra, a neurotransmitter with a similar action (yet less diffuse) as serotonin. Last, patients suffering to the chronic illness usually show severe mental retardation.

Rare symptoms

Most patients suffering from the chronic illness show somatic abnormalities such as large feet and unusual clumsiness, especially female patients.

In terms of social behavior, due to the abnormal development of the neuro-epiphysis, hypothalamus and subsequently brain cortex patients show some irregular symptoms described by an appreciation of infantile and ludicrous sensual gratifications such as french music and what they refer to as french "art". Some female patients have also exhibited affectionate or even abusive behavior (some are even bold enough to use the term 'molestation') towards younger members of the opposite sex.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Hatzfeldt_Syndrome". A list of authors is available in Wikipedia.
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