Calculi and memory

Temporary Memory Steal: Transient Global Amnesia Secondary to Nephrolithiasis

Transient global amnesia (TGA) is typified by an abrupt and transient anterograde amnesia, “with repetitive questioning and often variable retrograde amnesia persisting up to 24 hours.” A 54-year-old male presented to our emergency department with paroxysms of left-sided flank pain, suggestive of renal colic. Computed tomography (CT) of the abdomen/pelvis revealed a three-millimeter left ureterovesicular-junction calculus. Pain control proved difficult, necessitating multiple doses of opioid and non-opioid analgesia. Subsequently, the patient developed repetitive questioning and perseveration with anterograde amnesia with a negative CT brain and unremarkable further workup. He experienced a complete resolution of symptoms within a 24-hour period, with a discharge diagnosis of TGA secondary to nephrolithiasis. This is the third case of TGA attributed to nephrolithiasis in the medical literature.

Transient global amnesia after sexual intercourse

BACKGROUND

Transient global amnesia presents as paroxysmal, transient loss of memory function and has been shown to have a number of inciting factors.

AIMS

To report a case and its inciting factor in order to heighten awareness of the condition.

METHODS

A 56-year-old woman who presented with TGA after sexual intercourse is reported.

RESULTS

The episode of TGA resolved after 14 hours. Results of laboratory tests including MRI brain and MR angiogram and venogram were normal.

CONCLUSION

An inciting event can often be identified for TGA and a targeted history should be used to help elicit such events.

Cardiac arrest with cardiopulmonary resuscitation reduces dendritic spine density in CA1 pyramidal cells and selectively alters acquisition of spatial memory

The hippocampus is highly sensitive to ischemia and is one of the most extensively damaged regions of brain during cardiac arrest. Damage to hippocampus can subsequently lead to learning and memory deficits. The current study used the Morris water maze to characterize spatial learning and memory deficits elicited by 8 min of cardiac arrest with cardiopulmonary resuscitation (CA/CPR) in mice, which is associated with a 25-50% decrease in CA1 neurons. Mice were trained to navigate the water maze prior to CA/CPR or sham surgery (SHAM). They were retested in the water maze on days 7 and 8 postsurgery; both CA/CPR and SHAM groups were able to perform the task at presurgical levels. However, when the hidden platform was moved to a new location, the SHAM mice were able to adapt more quickly to the change and swam a shorter distance in search of the platform than did CA/CPR mice. Thus, CA/CPR did not affect the ability of mice to retain a previously learned platform location, but it did affect their ability to learn a new platform location. This behavioural impairment was correlated with dendritic spine density in the CA1 region of the hippocampus. Data presented here suggest that morphological changes, such as spine density, that occur in neurons that survive CA/CPR may be associated with cognitive impairments.