<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019ff895-3f1d-7471-8d23-4d0230bcfb91,g:9cafa5b0-45f4-4363-a00f-a6ec9996a7cd-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://www.heliusmedical.com/role/Cover" xlink:type="simple" xlink:href="hsdt-20260814.xsd#Cover"/>
  <link:presentationLink xlink:role="http://www.heliusmedical.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CoverAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019ff896-dbd3-7f25-9d0e-7ffaa7a05ed8" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_DocumentType_019ff896-dbd3-7f25-9d0e-7ffaa7a05ed8" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019ff896-dbd3-7061-b7e9-af1eb364c256" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_AmendmentFlag_019ff896-dbd3-7061-b7e9-af1eb364c256" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019ff896-dbd3-7ac6-93f3-f74bd2879a62" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:presentationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_DocumentPeriodEndDate_019ff896-dbd3-7ac6-93f3-f74bd2879a62" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019ff896-dbd3-7633-a854-d98ef7569e9f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:presentationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityRegistrantName_019ff896-dbd3-7633-a854-d98ef7569e9f" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019ff896-dbd3-7e34-a8ef-19f71fe322ed" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:presentationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityCentralIndexKey_019ff896-dbd3-7e34-a8ef-19f71fe322ed" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019ff896-dbd3-7f74-abd4-34814c9b2c87" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:presentationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019ff896-dbd3-7f74-abd4-34814c9b2c87" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019ff896-dbd3-7ff5-a3ed-fc0dd2ed8478" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:presentationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityFileNumber_019ff896-dbd3-7ff5-a3ed-fc0dd2ed8478" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019ff896-dbd3-7343-8f83-cd3ca587f0ac" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:presentationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityTaxIdentificationNumber_019ff896-dbd3-7343-8f83-cd3ca587f0ac" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019ff896-dbd3-7231-b472-c8730750792c" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:presentationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityAddressAddressLine1_019ff896-dbd3-7231-b472-c8730750792c" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019ff896-dbd3-7cf6-a728-27fee6a62346" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:presentationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityAddressCityOrTown_019ff896-dbd3-7cf6-a728-27fee6a62346" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019ff896-dbd3-788f-a15b-a075c7e4ada1" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:presentationArc order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityAddressStateOrProvince_019ff896-dbd3-788f-a15b-a075c7e4ada1" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019ff896-dbd3-75c6-9fc1-45e2e25e36c3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:presentationArc order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityAddressPostalZipCode_019ff896-dbd3-75c6-9fc1-45e2e25e36c3" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019ff896-dbd3-7cd0-bb45-e2659bfc7678" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:presentationArc order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_CityAreaCode_019ff896-dbd3-7cd0-bb45-e2659bfc7678" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019ff896-dbd3-7faa-9eae-11ba351024bf" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:presentationArc order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_LocalPhoneNumber_019ff896-dbd3-7faa-9eae-11ba351024bf" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_019ff896-dbd3-7937-92f7-61409bf2e4da" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_WrittenCommunications"/>
    <link:presentationArc order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_WrittenCommunications_019ff896-dbd3-7937-92f7-61409bf2e4da" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_019ff896-dbd3-785d-ab87-84ef42657f31" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SolicitingMaterial"/>
    <link:presentationArc order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_SolicitingMaterial_019ff896-dbd3-785d-ab87-84ef42657f31" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_019ff896-dbd3-7793-9a99-bd6fa4887f2b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementTenderOffer"/>
    <link:presentationArc order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_PreCommencementTenderOffer_019ff896-dbd3-7793-9a99-bd6fa4887f2b" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_019ff896-dbd3-78ad-ba94-02e50ec6abc3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:presentationArc order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_019ff896-dbd3-78ad-ba94-02e50ec6abc3" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019ff896-dbd3-76a6-b124-d6f241f4692d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:presentationArc order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_Security12bTitle_019ff896-dbd3-76a6-b124-d6f241f4692d" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019ff896-dbd3-715b-89cf-6261ffc6d1f8" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:presentationArc order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_TradingSymbol_019ff896-dbd3-715b-89cf-6261ffc6d1f8" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019ff896-dbd3-73b1-a0d6-9e9979ce07d4" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:presentationArc order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_SecurityExchangeName_019ff896-dbd3-73b1-a0d6-9e9979ce07d4" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019ff8a1-8e82-752f-9de8-64ebdc5a265a" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:presentationArc order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ff896-dbd3-79d6-b1bb-4842db96bfb6" xlink:to="loc_dei_EntityEmergingGrowthCompany_019ff8a1-8e82-752f-9de8-64ebdc5a265a" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </link:presentationLink>
</link:linkbase>
