Transient Gerstmann syndrome as manifestation of stroke: Case reportand brief literature review

INTRODUCTION

Gerstmann's syndrome (GS) is a rare clinical condition that has been extensivelystudied by neuroscience researchers, particularly in the field of neuropsychology.Classically, this syndrome comprises a tetrad of symptoms: acalculia, agraphia,finger agnosia and right-left disorientation.¹ The literature documents that lesions in the dominanthemisphere can result in these cognitive changes,² which are occasionally associated with aphasicdisorders.³ We report acase of transient GS in a young adult patient.

CASE REPORT

A 43-year-old male right-handed patient, a student in use of illegal anabolicsteroids with a 2-year history of mitral valve replacement (biological) and atrialfibrillation without regular follow-up, presented at the emergency room withcomplaints compatible with sudden onset of language impairments and rightsensorimotor hemiparesis with faciobrachial predominance. On admission assessment,vital signs were stable and the blood glucose test ruled out hypo or hyperglycemia.The general clinical exam revealed irregular heartbeat, systolic murmur in themitral region (3+/6+) radiating to the left midaxillary line, and no otherabnormalities. On the neurological exam performed around 6 hours after ictus (a fewminutes after patient arrival at hospital), the patient was alert, collaborative inperforming the exam and spatially and temporally well-oriented. The strength examrevealed labial commissure deviation to the left and paresis of the proximal rightupper limb (strength grade IV+). Results on coordination and sensory tests of allmodalities were normal.

Neuropsychological assessment revealed aphasia characterized by low fluency (speechoutput of less than 10 words per minute); repetition inability; difficulty in namingsimple objects and in spontaneous naming on word-list generation task (fewer than 12animals per minute); absence of ideomotor apraxia for transitive and intransitivegestures; agraphia characterized by difficulty writing letters and wordsspontaneously, dictated or copied; acalculia for low complexity addition andsubtraction sums; finger agnosia (inability to follow command to move specificfinger of one hand upon touching of finger on opposite hand by examiner, in additionto difficulty recognizing fingers of own hand) and right-left disorientation, forexample, when requested to point to right foot with left hand.

Cranial computed tomography (CT) exam on admission was normal while electrocardiogramdisclosed irregular rhythm and absence of p wave, with no ischemic changes. It isimportant to note that no echocardiographer was available at the time to provide anemergency assessment.

At the time the patient was seen by the neurology team, he was considered ineligiblefor endovenous thrombolysis owing to the time interval of over four and a half hoursbetween the onset of clinical symptoms and arrival at the emergency room. Submittedto clinical support, the patient attained a stable condition without complications.Approximately 30 hours after clinical symptoms onset, the patient had good generalhealth status and no motor deficits. Another neuropsychological assessment revealedpreserved comprehension, ability to produce complete simple and complex sentences,occasionally associated with difficulty in expression and in naming simple objects,and no abnormalities in writing letters, words or complete sentences, exhibitingpreserved right-left orientation and finger gnosia in response to the same promptsgiven in the admissions exam. Cranial CT performed 72 hours post-ictus revealed ahypodense area in the left inferior frontal lobe (Figure 1). Brain Magnetic Resonance Imaging (MRI) performed duringoutpatient follow-up disclosed hypersignal and restricted diffusion in the leftanterior and posterior insular cortex (Figures2 and 3), with sparing of thetopography corresponding to the angular and supramarginal gyri. During follow-up,the patient was referred for neuropsychological rehabilitation and to the outpatientclinic in use of warfarin as a secondary prophylactic.

Figure 1

Cranial Computed Tomography in axial section showing hypodense area inthe left inferior frontal gyrus topography.

Figure 2

Brain Magnetic Resonance Imaging (FLAIR) in axial section showinghypersignal in the left anterior and posterior insular cortextopography, with sparing of the left angular and supramarginal gyri.

Figure 3

Brain Diffusion Magnetic Resonance Imaging in axial section showingrestricted diffusion in the cortical region of the left insulartopography.

DISCUSSION

In 1924, Austrian neurologist Joseph Gerstmann described the case of a 53-year-oldpatient presenting with agraphia, acalculia, right-left disorientation anddifficulty moving specific fingers when requested by the examiner, clinical findingsrelated to cerebrovascular syndrome with left hemisphere involvement.²

Three years later, the same author reported two similar cases exhibitingconstructional apraxia, anomia for colors and difficulty reading numbers but notwords.⁴ However, it was in1940, when Gerstmann's work was published in English, that the syndrome became knownin the global academic milieu. In that same year, GS was characterized by the tetradcomprising: agraphia, acalculia, finger agnosia and right-leftdisorientation.¹

In the decades that followed, a strong relationship between lesions in the dominanthemisphere and GS was confirmed, more specifically in the angular gyrus of theparietal lobe.^5-8 Lesions in this gyrus are associated predominantlywith the symptoms of agraphia and acalculia.⁹

In 1984, Morris et al. reported the case of a patient with transient findingscompatible with GS after stimulation of the posterior perisylvian region, morespecifically in the transition between the angular and supramarginal gyri.¹⁰ In 2003, Roux et al. foundabnormalities involving writing, calculating and finger recognition using the brainmapping technique in the left angular gyrus of 6 right-handed patients submitted totumor resection.¹¹

Even in cases where the angular gyrus is spared, lesions immediately subcortical tothis area, or involving the mesial occipital cortex or splenium of the corpuscallosum, may also lead to agraphia and/or acalculia.¹² In addition, in cases of GS with sparing of theclassically involved areas, the hypothesis of disconnection syndrome involvinglesions to association fibers joining different cortical and subcortical regionsshould also be considered.¹³

Seven years ago, Rusconi et al. revisited various aspects of GS, including theirfirst description and the importance of the applicability of the concept of thedisconnection syndrome in this context. The authors stated that certain recentstudies employing the neurofunctional imaging technique, such as those performedusing tractography, suggest that the group of clinical symptoms of GS perhaps shouldnot be attributed exclusively to one specific neuronal group.¹⁴ This evidence again brought to thefore criticisms of Gerstmann made by some authors, such as Critchley, in themid-1960s, when the localizing value of the syndrome was questioned.¹⁵

In view of these considerations, it is noteworthy to mention the insular cortex andits interaction with other areas. This structure has a reciprocal connection withthe parietal operculum, anterior inferior parietal cortex, somatosensory cortex,retroinsular parietal region,¹⁶orbitofrontal and pre-frontal cortex, frontal operculum and efferent pathways to theinferior frontal gyrus and Brodmann's areas 6 and 12.¹⁷ As is known, lesions located immediately deep tothe insular cortex, more precisely in the extreme capsule, may cause disconnectionof short association fibers between frontal and parietal operculae and lead todisruption of frontoparietal circuitry.^18,19

In 2014, a case was reported of an elderly patient with dyscalculia, dysgraphia andright-left confusion (without finger agnosia) secondary to ischemic injury of theleft posterior insula and temporal-parietal operculum, without lesions of theangular and supramarginal gyri.¹⁹

Recently, several articles have suggested a relationship between the frontal lobe andGS. In 2013, Heymi Lee et al. published two cases in which Brain MRI disclosedmiddle and inferior frontal gyri and basal ganglia impairment as a result ofischemic stroke with hemorrhagic transformation in the first case, and involvementof the inferior frontal gyrus, pars opercularis and triangularis secondary to thecompression effect by glioma in the second case. Neurological exams in both patientsrevealed the four typical symptoms of GS.²⁰

In 2016, Eun-Ju Lee et al. published two cases of patients that had clinical symptomscompatible with the GS tetrad, where ischemic lesion of the left medial frontal lobewas found on Brain MRI, with sparing of the angular and supramarginal gyri andadjacent structures. In these articles, the authors attributed the findings to thepossibility of disconnection between the association fibers and suggested theimportance of the cortical and subcortical regions of the left frontal lobe in thephysiopathogenesis of GS, given there is a strong connection between these areas andthe parietal lobe.²¹

Our review of the literature lead us to believe that the changes initially observedon the patient's neurological exam may have been attributed to mechanisms related tothe disconnection syndrome secondary to ischemic injury of the territories ofassociation fibers between frontal and parietal lobes, given that lesions werepresent in the inferior frontal gyrus and insular cortex of the dominanthemisphere.

Considering that the middle cerebral artery irrigates the insular cortex and segmentsof the frontal and parietal lobe, an alternative hypothesis for this case might bethe possible occurrence of reperfusion in the penumbra area after clinicalmanagement.