Severe amnesia after a restricted lesion in the left hippocampal body

Insulin-Like Growth Factor 2 (IGF-2) Regulates Neuronal Density and IGF-2 Distribution Following Hippocampal Intracerebral Hemorrhage

BACKGROUND

The insulin-like growth factor 2 (IGF-2) is a growth factor and anti-inflammatory cytokine that plays a crucial role in memory consolidation. However, the precise role of this factor in acute brain damage is still unclear. The present study aimed to evaluate the variations in hippocampal IGF-2 distribution on different days and investigate the effect of recombinant IGF-2 on memory cell density, and IGF-2 distribution following acute hippocampal damage resulting from intracerebral hemorrhage (ICH).

METHODS

ICH was induced by injection of 100 μL of autologous blood into the left hippocampus of 72 male Sprague-Dawley rats. Recombinant IGF-2 was injected into the damaged hippocampus 30 min post-induction of ICH in the ICH-IGF-2 group. Then, on postoperative days 1, 3, 7, and 14, samples of brain tissue were collected to perform histopathological and immunohistochemical examinations.

RESULTS

The stereological study indicated that the volume of the hippocampus and the number of neurons had a significant reduction, and the infarct volume had a significant increase following ICH. Following the injection of IGF-2, a significant improvement was observed in stereological studies. Immunohistochemical data showed that IGF-2 distribution increased in the hippocampus on different days after ICH, and IGF-2 injection led to a dramatic reduction in this distribution.

CONCLUSIONS

In summary, the gradual increase of endogenous IGF-2 as growth and anti-inflammatory factor following hemorrhagic stroke reveals a critical role of this factor in brain recovery after injury. Moreover, the injection of IGF-2 can prevent cell death and alleviate the damage caused by the hemorrhagic stroke.

Selective anterograde amnesia with thalamus and hippocampal lesions in neuro-Behcet's disease

Anterograde amnesia and minimal retrograde amnesia with thalamic and hippocampal lesions in neuro-Behcet's disease is rare. A 50-year-old man presented with forgetfulness and severe memory disturbance after suffering multiple oral and genital aphthous ulcers with erythema nodosum. A neurological examination and a neuropsychological assessment revealed prominent anterograde memory impairment without focal neurological deficits. On brain MRI there were high signal intensity lesions involving right anterior thalamus, left posterior basal ganglia, and left hippocampus. This is a quite selective anterogrde memory deficit in a case of neuro-Behcet's disease caused by parenchymal lesions in the thalamus and hippocampus.