K. Arita et al., The relationship between magnetic resonance imaging findings and clinical manifestations of hypothalamic hamartoma, J NEUROSURG, 91(2), 1999, pp. 212-220
Object. Hypothalamic hamartoma is generally diagnosed based on its magnetic
resonance (MR) imaging characteristics and the patient's clinical symptoms
, but the relationship between the neuroradiological findings and clinical
presentation has never been fully investigated. In this retrospective study
the authors sought to determine this relationship.
Methods. The authors classified 11 cases of hypothalamic hamartoma into two
categories based on the MR findings. Seven cases were the "parahypothalami
c type," in which the hamartoma is only attached to the floor of the third
ventricle or suspended from the floor by a peduncle. Four cases were the "i
ntrahypothalamic type," in which the hamartoma involved or was enveloped by
the hypothalamus and the tumor distorted the third ventricle.
Six patients with the parahypothalamic type exhibited precocious puberty, w
hich was controlled by a luteinizing hormone-releasing hormone analog, and
one patient was asymptomatic. No seizures or mental retardation were observ
ed in this group. All patients with the intrahypothalamic type had medicall
y intractable seizures, and precocious puberty was seen in one. Severe ment
al retardation and behavioral disorders including aggressiveness were seen
in two patients. The seizures were controlled in only one patient, in whom
stereotactically targeted irradiation of the lesion was performed.
This topology/symptom relationship was reconfirmed in a review of 61 report
ed cases of hamartoma, in which the MR findings were clearly described. The
parahypothalamic type is generally associated with precocious puberty but
is unaccompanied by seizures or developmental delay, whereas the intrahypot
halamic type is generally associated with seizures. Two thirds of patients
with the latter experience developmental delays, and half also exhibit prec
ocious puberty.
Conclusions. Classification of hypothalamic hamartomas into these two categ
ories based on MR findings resulted in a clear correlation between symptoms
and the subsequent clinical course.