Short-Term Memory Impairment and Left Dorsolateral Prefrontal Cortex Dysfunction in the Orthostatic Position: A Single Case Study of Sinking Skin Flap Syndrome.

Luca Sebastianelli,Viviana Versace,Leopold Saltuari,Kathrin Malfertheiner,Gertraud Gisser,Verena Stoll,Sara Martignago,Marco Lavoriero,Stephan Obletter

doi:10.1155/2015/318917

Luca Sebastianelli, Viviana Versace + Show 7 more

Open Access

https://doi.org/10.1155/2015/318917

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Abstract

We describe the case of a patient who underwent craniectomy for hemorrhage of the left parietal lobe. Three weeks later, orthostatic memory impairment was detected as initial symptom of sinking skin flap syndrome (SSFS). This deficit was examined by neuropsychological testing and associated with a posture-dependent increase in the delta/alpha ratio at the F3 electrode, an electroencephalographic (EEG) index related to brain hypoperfusion. This EEG spectral alteration was detected in a brain region that includes the left dorsolateral prefrontal cortex, an area known to be involved in memory processing; therefore we hypothesize that SSFS induced reversible hypoperfusion of this otherwise undamaged cortical region. Neither of these findings was present after cranioplasty. This case suggests that SSFS may induce neuropsychological deficits potentially influencing outcome in the postacute phase and is further evidence supporting the clinical benefits of early cranioplasty.

Highlights

Skin displacement is a consequence of the gradient between intracranial and atmospheric pressure and leads to dysfunction in the compressed cerebral structures, by inducing region-specific perfusion deficit
Disturbances in memory, executive, and planning functions are described in patients who underwent frontal craniectomy [3]
Other factors, such as disturbances in cerebrospinal fluid (CSF) circulation, and generalized dysregulation of cerebral blood flow may play a role in nonfocal neurological deficits, as described in the “syndrome of the trephined,” which includes headache, dizziness, alterations in behaviour and mood, seizures, and fatigue [4]

Summary

Introduction

Skin displacement is a consequence of the gradient between intracranial and atmospheric pressure and leads to dysfunction in the compressed cerebral structures, by inducing region-specific perfusion deficit. Disturbances in memory, executive, and planning functions are described in patients who underwent frontal craniectomy [3] Other factors, such as disturbances in cerebrospinal fluid (CSF) circulation, and generalized dysregulation of cerebral blood flow may play a role in nonfocal neurological deficits, as described in the “syndrome of the trephined,” which includes headache, dizziness, alterations in behaviour and mood, seizures, and fatigue [4]. “Paradoxical herniation” is the most advanced stage of the syndrome This potentially life-threatening clinical picture occurs when the sinking flap induces displacement of brain midline structures. Ratio between power of alpha and delta band (DAR) has been proven to be an early index of brain hypoperfusion and to have better sensibility and specificity for brain hypoperfusion with respect to other qEEG indexes [8]

Case Presentation

Discussion

Findings

F7 C3 T3