It is controversial whether isolated lesions of mammillothalamic tract (MTT) produce significant amnesia. Since the MTT is small and adjacent to several important structures for memory, amnesia associated with isolated MTT infarction has been rarely reported. We report a patient who developed amnesia following an infarction of the left MTT that spared adjacent memory-related structures including the anterior thalamic nucleus. The patient s memory deficit was characterized by a severe anterograde encoding deficit and retrograde amnesia with a temporal gradient. In contrast, he did not show either frontal executive dysfunction or personality change that is frequently recognized in the anterior or medial thalamic lesion. We postulate that an amnesic syndrome can develop following discrete lesions of the MTT.
Aged ; Amnesia/*etiology ; Cerebral Infarction/*complications ; Humans ; Male ; Mamillary Bodies/*physiopathology ; Neuropsychological Tests ; Thalamus/*physiopathology

We present here a case in which functional MR imaging (fMRI) was done for a patient who developed retrograde psychogenic amnesia for a four year period of her life history after a severe stressful event. We performed the fMRI study for a face recognition task using stimulation with three kinds of face photographs: recognizable familiar faces, unrecognizable friends' faces due to the psychogenic amnesia, and unfamiliar control faces. Different activation patterns between the recognizable faces and unrecognizable faces were found in the limbic area, and especially in the amygdala and hippocampus.
*Stress Disorders, Post-Traumatic ; *Magnetic Resonance Imaging ; Humans ; Hippocampus/physiology ; Female ; Amygdala/physiology ; Amnesia, Retrograde/*diagnosis/*etiology ; Adult

We report a 61-year-old right-handed man developing disturbance of memory after a discrete thalamic infarction. Neuropsychological assessment revealed deficits in memory with retrograde and anterograde components, especially for verbal material. Brain MRI showed a left anterior thalamic infarction with normal angiographic findings. Despite the small lesion in the thalamus, he showed prolonged memory disturbance and a Brain SPECT image revealed decreased uptake in the ipsilateral fronto-temporo-parietal cortex and contralateral cerebellum. This diaschisis, a phenomenon caused by disconnection of the neural pathway helped us to evaluate the functional state of the patient and this imaging technique was valuable for obtaining to get more information for the evaluation of the neurological state and neuronal connections. In conclusion our findings correspond well with the understanding of amnesia as a disconnection syndrome because of the evidence of diaschisis on the Brain SPECT image.
Amnesia/*etiology ; Brain/*radionuclide imaging ; Case Report ; Cerebellum/radionuclide imaging ; Cerebral Infarction/*complications/radionuclide imaging ; Human ; Male ; Middle Age ; Thalamic Diseases/*complications/radionuclide imaging ; *Tomography, Emission-Computed, Single-Photon

The mechanism of chronic pain is very complicated. Memory, pain, and opioid dependence appear to share common mechanism, including synaptic plasticity, and anatomical structures. A 48-yr-old woman with severe pain caused by bone metastasis of breast cancer received epidural block. After local anesthetics were injected, she had a seizure and then went into cardiac arrest. Following cardiopulmonary resuscitation, her cardiac rhythm returned to normal, but her memory had disappeared. Also, her excruciating pain and opioid dependence had disappeared. This complication, although uncommon, gives us a lot to think about a role of memory for chronic pain and opioid dependence.
Amnesia/*diagnosis ; Anesthesia, Local/adverse effects ; Bone Neoplasms/drug therapy/radiotherapy/secondary ; Breast Neoplasms/drug therapy/pathology/radiotherapy ; *Cardiopulmonary Resuscitation ; Electroencephalography ; Female ; Heart Arrest/etiology ; Humans ; Magnetic Resonance Imaging ; Mepivacaine/adverse effects ; Middle Aged ; *Pain Management ; Seizures/etiology ; Tomography, X-Ray Computed

The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.
Amnesia ; chemically induced ; Animals ; China ; epidemiology ; Ciguatoxins ; toxicity ; Diarrhea ; chemically induced ; Dinoflagellida ; Environment ; Eukaryota ; chemistry ; Eutrophication ; Fisheries ; Food Contamination ; Foodborne Diseases ; epidemiology ; etiology ; Humans ; Kainic Acid ; analogs & derivatives ; poisoning ; Lethal Dose 50 ; Marine Toxins ; chemistry ; poisoning ; toxicity ; Neurotoxicity Syndromes ; etiology ; Okadaic Acid ; poisoning ; Oxocins ; poisoning ; Paralysis ; chemically induced ; Seawater ; Shellfish Poisoning