Yang et al. BMC Neurology
(2020) 20:120
https://doi.org/10.1186/s12883-020-01698-0

CASE REPORT

Open Access

Uncrossed corticospinal tracts in a patient
with ichthyosis and hemiparesis: a case
report
Huijia Yang1†, Hongwei Zhou2† and Jing Miao1*

Abstract
Background: Anomalies of pyramidal tract decussation are rare phenomena that can be caused by ectodermal
dysplasia. Herein, we describe a patient with ichthyosis who exhibited ipsilateral hemiparesis after stroke and whose
neuroimaging results showed evidence of motor control being provided by the ipsilateral motor cortex.
Case presentation: A 24-year-old right-handed man presented with skin abnormalities, sudden-onset left hemiparesis,
and dysarthria. He exhibited a mild-to-moderate left-sided weakness (grade 4 on the Medical Research Council scale).
Magnetic resonance imaging revealed an acute infarct in the left corona radiata. Diffusion tensor imaging revealed
uncrossed corticospinal tracts. Next-generation sequencing identified heterozygous FLG mutations. The patient was
diagnosed with cerebral infarction and ichthyosis vulgaris and was treated with aspirin (100 mg/d). His symptoms
gradually dissipated.
Conclusions: This case suggests that pyramidal decussation anomalies can be associated with ichthyosis. Patients with
ichthyosis should therefore be evaluated for nerve involvement.
Keywords: Uncrossed corticospinal tracts, Ihthyosis, DTI, Ischemic stroke, Ipsilateral hemiparesis

Background
Supratentorial stroke is widely known to cause neurological impairment on the contralateral side of the body.
Previous neuroanatomic studies have shown that the
primary motor cortex predominantly controls the contralateral half of the body [1]. Corticospinal tract decussation
anomalies are mostly nonspecific and coincidental. Since
the first report [2], such anomalies have been described in
patients with posterior fossa malformations and extensive
brainstem malformations [3]. Furthermore, a few reports
have described ipsilateral hemiparesis in patients with
agenesis of the corpus callosum and scoliosis [4, 5], and
such reports show that pyramidal tract abnormalities can
* Correspondence: 475764792@qq.com
Huijia Yang and Hongwei Zhou are co–first authors.
1
Department of Neurology and Neuroscience Center, The First Hospital of
Jilin University, Changchun 130021, China
Full list of author information is available at the end of the article

arise in patients with developmental disorders. Herein, we
describe a patient with ichthyosis who exhibited ipsilateral
hemiparesis after stroke and whose neuroimaging results
showed evidence of motor control being provided by the
ipsilateral motor cortex.

Case presentation
A 24-year-old man presented with sudden-onset mild leftsided hemiparesis that had manifested 2 days earlier. He
had no history of smoking, or excessive alcohol consumption. A medical examination showed that he had dry and
scaly skin (Fig. 1). He claimed to have experienced his skin
disorder for 20 years. On neurological examination, he
was conscious and alert. No other focal neurologic deficits
were noted except mild left-sided hemiparesis.
Initial head CT demonstrated no acute infarction. The
following day, brain magnetic resonance imaging (MRI)
(Siemens, Germany) with diffusion-weighted sequences

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Fig. 1 The skin on the patient’s shins was dry and scaly

revealed punctate areas of restricted diffusion in the left
corona radiata that represented small acute infarct
(Fig. 2a). Magnetic resonance angiography revealed no
significant flow-limiting stenosis. Because the MRIdetected lesions were ipsilateral to the paralyzed limb,
the patient underwent diffusion tensor imaging (DTI)
(Siemens Magnetom trioatim 3.0 T, Siemens Leonardo)
tractography, which revealed uncrossed corticospinal
tracts (Fig. 2b). The level of D-dimer was within the normal range in our patient who without history of hypertensive disease, in addition, no abnormalities were found
in carotid ultrasound, cervical MRI, echocardiography,
foaming test and microembolism monitoring, the probabilities of arterial dissection or patent foramen ovale
were reduced.
Cerebrovascular risk factors such as serum lipid, uric
acid, homocystein, high-sensitivity C-reactive protein, B12
vitamin, folate, fasting blood glucose were all within the
normal range and the patient has no history of hypertension, diabetes mellitus, smoking, and alcohol

consumption. Body mass index (BMI), routine blood test,
coagulation routine, renal function and liver function,
erythrocyte sedimentation rates (ESR), HIV serology,
syphilis serology, serum lactate, anti-nuclear antibody
were all normal or negative. An electrocardiogram and a
transthoracic echocardiogram revealed no sources of cardiac embolism. Besides, the patient’s other MRI sequences
were negative, so we could exclude cerebral small vessel
disease and microbleeds. Noteworthy, his skin was abnormal for about 20 years. We performed a genetic test on
the patient. However, next-generation sequencing of a
DNA sample identified two known heterozygous FLG
nonsense mutations: (c.3905C > A, p.Ser1302Ter)(which
was inherited from his father) and (c.5368C > T,
p.Gln1790Ter) (which was inherited from his mother) [6,
7]. The two mutations have an effect on the protein
functions.
Based on these genetic findings and the patient’s 20year history of skin complaints, the patient was diagnosed with ichthyosis vulgaris and cerebral infarction.

Fig. 2 a. Diffusion-weighted imaging revealed lesions with strong signal intensities and decreased apparent diffusion coefficients. b. Diffusion
tensor imaging tractography revealed uncrossed corticospinal tracts. The red arrow shows the infarcted area in which the corticospinal tract
was destroyed

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His left-side hemiparesis gradually dissipated after symptomatic treatment. Aspirin therapy played a crucial role
in the secondary prevention of ischemic stroke. After
discharge, the patient continued to take aspirin with
daily dose of 100 mg.

Discussion
Ichthyosis is a group of disorders resulting from variants
in more than 50 genes, and it is characterized by thickening and splitting of the skin [8]. Roy et al. [9] reported
that spasticity, epilepsy, and intellectual disability are the
primary neurological findings. Our case represents the
first report of cerebral infarctions as neurological comorbidities in a patient with ichthyosis.
We diagnosed our patient with ichthyosis vulgaris,
which typically results from heterozygous or compound
heterozygous FLG mutations. However, all forms of ichthyosis have been associated with protein and lipid abnormalities [8]. Our young patient had almost no risk
factors for cerebrovascular disease, indicating that ichthyosis might be associated with the development of infarction. Interestingly, our patient exhibited brain lesions
that were ipsilateral to his paralyzed limb.
Previous reports suggested anomalies of the dorsal column
medial lemniscus pathway associated with uncrossed pyramidal tracts and abnormalities of bimanual tasks in pyramidal
tract crossing anomalies [10–12]. After we had performed a
careful physical examination and asked history of disease entirely, not found any sensory abnormality, synkinetic contralateral movements or mirror movement in this patient.
Donkelaar et al. [3] described the development and potential malformations of the human pyramidal tract and
noted that certain malformations may lead to pyramidal
decussation anomalies. Decussation anomalies of the corticospinal tracts can be found in association with other
cerebral anomalies, such as congenital scoliosis, corpus
callosum agenesis, occipital encephaloceles, posterior fossa
malformations, Dandy-Walker malformations, Joubert
syndrome, and extensive brainstem malformations [3].
In terms of embryogenesis, the skin and nervous system are homologous to the ectoderm. Congenital ectodermal dysplasia causes simultaneous neurological and
cutaneous lesions, resulting in various clinically complex
hereditary neurocutaneous syndromes. Sprecher et al.
[13] described a novel neurocutaneous disease called
CEDNIK syndrome that is characterized by cerebral dysgenesis, neuropathy, ichthyosis, and keratoderma. We
therefore speculate that our patient’s pyramidal decussation anomalies may be caused by the same FLG mutations that cause his ichthyosis.
Conclusions
In conclusion, we identified uncrossed pyramidal tracts
in a patient with clinically and genetically confirmed

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ichthyosis and there might be a pathophysiological association, becoming clinically relevant in certain scenarios,
such as stroke.
Abbreviations
CT: Computed tomography; MRI: Magnetic resonance imaging; DTI: Diffusion
tensor imaging
Acknowledgments
We are grateful to the patient who was willing to share his medical data.
Availability of data and material
Not applicable.
Authors’ contributions
HJ-Y: drafting the manuscript; accepts responsibility for conduct of research
and final approval. HW-Z: analysis or interpretation of data, accepts responsibility for conduct of research and final approval, acquisition of data, study
supervision. J-M: critically revised and gave final approval for publication of
the paper. All author have read and approved the manuscript.
Funding
This work was supported by the National Natural Science Foundation of
China (grant number 81974191). The funding body played no role in the
design of the study, in writing the manuscript, nor in the collection, analysis,
or interpretation of the data.
Ethics approval and consent to participate
Not applicable.
Consent for publication
Written informed consent was obtained from the patient for the publication
of this case report.
Competing interests
The authors declare that they have no competing interests.
Author details
1
Department of Neurology and Neuroscience Center, The First Hospital of
Jilin University, Changchun 130021, China. 2Department of Radiology, The
First Hospital of Jilin University, Changchun 130021, China.
Received: 15 February 2020 Accepted: 26 March 2020

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